Jump to content

Help with a Year 4 maths problem please
DH & I have several different answers


  • Please log in to reply
53 replies to this topic

#1 ~*Amethyst*~

Posted 11 February 2013 - 06:42 PM

Can anyone help in how to work out a 'Family Maths Question' please.

Family Maths Challenge 2

At your party you have decided to serve triple decker ice creams!
* There are 5 yummy flavours - peppermint, chocolate, strawberry, banana and tutti frutti.
  * How many combinations of three flavours could you create?
  * How many combinations of three flavours could you create if one flavour is always chocolate?
  * How many combinations all together (including 3 scoops the same, 2 the same and one different)?

XxxAmethyst


#2 secret~sammy

Posted 11 February 2013 - 06:49 PM

1) 5 chose 3 = 10

nCr = n! / (n - r)! r!

nCr = 5!/ (5 - 3)! 3!
nCr = 5!/ 2! 3!
nCr = (5 * 4 * 3 * 2 *1) / (2 * 1)(3 * 2 * 1)
nCr = 120 / (2 * 6)
nCr = 120 / 12
nCr = 10

2) 4 choose 2 (because 1 is always choc) = 6 by the formula above

3) 5^3 = 125

#3 Georgie01

Posted 11 February 2013 - 06:50 PM

QUOTE
How many combinations of three flavours could you create?


5x4x3=60 (you have 5 choices for the first flavour, then 4 for the second, 3 for the third since you aren't allowed to repeat any flavours)

QUOTE
* How many combinations of three flavours could you create if one flavour is always chocolate?


1x4x3=12 (1 choice is chocolate then 4 (all except chocolate) then 3 (not chocolate and not the second flavour)

QUOTE
How many combinations all together (including 3 scoops the same, 2 the same and one different)?


5x5x5=125 (because you can choose any of the five flavours for each scoop)

(hoping that I haven't done something wrong, seems to make sense original.gif )

#4 FeralCrazyMum

Posted 11 February 2013 - 06:51 PM

OMG I can't understand that formula ... it's not really a Year 4 question???
ETA: Georgie01, that answer makes more sense to me, still seems difficult for the age, but that could be because of my lack of maths skills.

Edited by CrazySingleMum, 11 February 2013 - 06:52 PM.


#5 Peppery

Posted 11 February 2013 - 06:54 PM

1. 15

2. 6

3. 125

Honestly these are guesses, my father was a mathematician (retired) would be absolutely horrified at my lack of mathematical reasoning

#6 Agnodice the Feral

Posted 11 February 2013 - 06:56 PM

Georgie's answer is correct.

I remember doing combinations in primary school.

#7 libbylu

Posted 11 February 2013 - 07:00 PM

Does the order of the flavours matter? If not, then the first poster is correct, if not, then the second poster is correct!
Does seem very complex for year 4.

#8 jayskette

Posted 11 February 2013 - 07:01 PM

1) 5*4*3
2) 4*3*2 - edited to say - oops... should be 4*3
3) 5*5*5

This is actually an extension maths question... unless the grade 4 people are smarter than when I did this as an extension when I was in year 4... lol

Try this one (another "extension" question on ratios that I actually got in year 4)

There is a piece of orchestral music that is played by 60 Strings, 60 Woodwind and 40 Brass, and it lasts 2 minutes 35 seconds.
How long will the music take to be played if it is played by 40 Strings, 30 Woodwind and 20 Brass?

ROFL

Edited by jayskette, 11 February 2013 - 07:03 PM.


#9 Georgie01

Posted 11 February 2013 - 07:05 PM

My grade 4 has done a little bit of this sort of thing - I work through it with him the way that I did here. It can help to use a diagram or find five different things an do a bit of a model to understand the reasoning.

I haven't had to use factorials with him as the worksheets ask him to explain how he thought things through and I'm fairly sure he hasn't learned factorials/combinations/permutations formally.

QUOTE
Does the order of the flavours matter? If not, then the first poster is correct, if not, then the second poster is correct!


Ahhh, thank you! I need to brush up.

Yes, my answers assume that choc/strawberry/banana is different to choc/banana/strawberry, Secret~Sammy's solution calls those the same...

Reading the question again Secret Sammy is right because the question asks for combinations so it's implied that the order doesn't matter and choc/strawberry/banana=strawberry/banana/choc etc.  Not sure how I'd help a year 4 work through that logically other than with a chart (assuming they haven't actually been taught the formula)

Edited by Georgie01, 11 February 2013 - 07:23 PM.


#10 amabanana

Posted 11 February 2013 - 07:06 PM

QUOTE (jayskette @ 11/02/2013, 08:01 PM) <{POST_SNAPBACK}>
There is a piece of orchestral music that is played by 60 Strings, 60 Woodwind and 40 Brass, and it lasts 2 minutes 35 seconds.
How long will the music take to be played if it is played by 40 Strings, 30 Woodwind and 20 Brass?


roll2.gif


Edited by amabanana, 11 February 2013 - 07:07 PM.


#11 secret~sammy

Posted 11 February 2013 - 07:10 PM

Whilst I still think I'm right  and the order of the flavours doesn't matter  cool.gif  -  Now that I think about it I suspect for a year 4 question the answer they are looking might be Georgie's one.

#12 secret~sammy

Posted 11 February 2013 - 07:13 PM

Whilst I still think I'm right  and the order of the flavours doesn't matter  cool.gif  -  Now that I think about it I suspect for a year 4 question the answer they are looking might be Georgie's one.

#13 ~*Amethyst*~

Posted 11 February 2013 - 07:14 PM

This was in DS homework book to be done tomorrow night as a family - no guidance - no instructions.

DH & I have spent the last 2 hours working on it & still aren't sure that we have calculated it correctly.

The answers are:

10

6

41

So it seems secret-Sammy was closest & Georgie's answer is incorrect?

How on earth are we supposed to explain this to our 9 year old & what is the purpose of such homework?

I find it very frustrating.

XxxAmethyst

#14 ~*Amethyst*~

Posted 11 February 2013 - 07:14 PM

This was in DS homework book to be done tomorrow night as a family - no guidance - no instructions.

DH & I have spent the last 2 hours working on it & still aren't sure that we have calculated it correctly.

The answers are:

10

6

41

So it seems secret-Sammy was closest & Georgie's answer is incorrect?

How on earth are we supposed to explain this to our 9 year old & what is the purpose of such homework?

I find it very frustrating.

XxxAmethyst

#15 HeroOfCanton

Posted 11 February 2013 - 07:24 PM

This is why I hated mathematics in primary school (and subsequently in secondary).

If you ever came across this in real life, would you care how many combinations you could make, or just be glad you could have 3 flavours of ice cream at once? Tounge1.gif

#16 PatG

Posted 11 February 2013 - 07:24 PM

Are you saying that the answers given are 10, 6 and 41?

If you are happy with 60 (5*4*3) as total permutations (order does matter) then try the following:

Each permutation of a, b, c can be written in 6 different ways (a, c, b etc).  Therefore to get the total combinations you need to divide 60 by 6 to get rid of the repeats, leaving 10.

Do the same with chocolate start - 1 x 4  x 3 = 12 , divide by 2 combinations of the second two scoops = 6

My solution to part c - total variations including multiple of the same flavour:

10 different ways to have 3 different flavours
5 different ways to have all the same flavour
20 ways to have 2 scoops the same and one diff  (4 different ways to have 2 scoops of chocolate and one other, multiply by the 5 flavours you could have two scoops of)

Total:  35.

I don't know what the other 6 are.....  The part b answer (6) is included in part a.

this webiste seems to agree with me 35 as an answer  I'm guessing I'm mis interpreting something

Edited by PatG, 11 February 2013 - 07:53 PM.


#17 FeralZombieMum

Posted 11 February 2013 - 07:30 PM

Ok I cheated and googled it.
http://www.docstoc.com/docs/134459705/Family-Maths-Challenge

There are 10 flavours of 3 combinations.
There are 6 combinations if one flavour is always chocolate.
There are 41 combinations altogether.


#18 ~*Amethyst*~

Posted 11 February 2013 - 07:30 PM

Yes PatG.  I got the second answer, DH the first & neither of us the last!

XxxAmethyst

#19 Lucrezia Borgia

Posted 11 February 2013 - 07:31 PM

The answer is 47


#20 Peppery

Posted 11 February 2013 - 07:32 PM

QUOTE (ZombieMum @ 11/02/2013, 08:30 PM) <{POST_SNAPBACK}>
Ok I cheated and googled it.
http://www.docstoc.com/docs/134459705/Family-Maths-Challenge

There are 10 flavours of 3 combinations.
There are 6 combinations if one flavour is always chocolate.
There are 41 combinations altogether.


Woohoo I got one right!!!!!!

#21 PatG

Posted 11 February 2013 - 07:35 PM

Sorry, have been adding to my prior post.... missed some of the updates.

#22 FeralZombieMum

Posted 11 February 2013 - 07:36 PM

The key word is combination.
QUOTE
Mathematicians eat ice cream just like anyone else.
But sometimes they take longer to make up their mind about what flavour of ice cream they would like to have, especially when they want a double scoop ice cream and there are 31 different flavours to choose from.
If I want a double scoop ice cream cone how many possible double scoop cones are there to choose from?

Now that’s a problem!!!


It has to do with things called  ‘COMBINATIONS’ and ‘PERMUTATIONS’.

If you think it doesn’t matter which flavour is on
top and which one is on the bottom,
then you are thinking about COMBINATIONS.


But if you think that a double scoop ice cream cone with strawberry on the top and lemon on the bottom is not the same as lemon on the top and strawberry on the bottom, then you are thinking about PERMUTATIONS.

There is a big difference.


#23 Georgie01

Posted 11 February 2013 - 07:43 PM

Oh, who knew there were solutions online! A couple of those maths challenges have taken us hours too.

What I will do when my year 4 comes home with that one is to sit down with 5 coloured textas and a big piece of paper and work through it.



#24 ~*Amethyst*~

Posted 11 February 2013 - 07:45 PM

I can't access that website on the iPad Zombiemum? It wants me to download something & then to enter my credit card details?

XxxAmethyst

#25 FeralZombieMum

Posted 11 February 2013 - 07:48 PM

It didn't explain it, just had the answers, so you don't need to view it online - plus you already knew the answers anyway. original.gif




1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users

 

Special offer: The Baby & Toddler Show 2014

At The Baby & Toddler Show, you?ll find everything you need to get ready for your new arrival and guide you through the early weeks and years of parenting.

An open letter to Tony Abbott: please salvage our super

We face financial ruin, but most of us don?t realise it. If we don?t act together to salvage our superannuation, I have no doubt the new GFC will be the Girls? Financial Crisis.

'I'm happy to know I'm changing lives': surrogate mum of two

I know that once the baby is born, I will focus on the gift I have given, and watch the parents with their new child. I can't wait for that day.

Birth trauma and the issue of informed consent

There is a perception that women should just be happy they have a healthy baby in their arms. But for women who experienced birth trauma, there's a lot more to it.

Tips for managing pollen allergies and hayfever

They're simple tips, but they can have a big impact on those who suffer from hayfever and pollen allergies.

Ada Nicodemou shares tribute to her stillborn baby

Just over one month since Ada Nicodemou and her husband lost their second son, the Home and Away star has shared a touching poem for her baby.

Mum causes stir breastfeeding on train

?To the woman breastfeeding her kid on the train. Seriously! On the train?" began the letter of complaint.

10 things they don?t tell you about being pregnant

As I slowly waddle my ever-changing pregnant body towards the finishing line of my due date, it?s becoming increasingly clear there are a lot of things they just don?t tell you about pregnancy.

Overcoming a fear of the dark

A toddler's fear of the dark is very normal, but there are ways parents can help children through this stage in their development.

Kids, TV and movies: how young is too young?

It seems you don't have to throw the TV and iPad out the window - it all boils down to moderation, supervision and interaction.

Video: Baby's first birthday is a special day for mum, too

?A baby?s first birthday is also mum?s first birthday.?

The day Supernanny came to tea

Prince William's favourite celebrity child trainer Jo Frost puts Bryony Gordon and her toddler through their paces.

The words I hated hearing as new mum

It was less than a week after my son was born that I first heard it - from my mother.

To the pharmacist who sold me baby formula

On the rare occasion I catch sight of you at school, or around town, I think back to our earliest exchange. I?m sure you have no recollection of it at all.

Babies may benefit from autism therapy

Children showing signs of autism don't usually receive early intervention until well into toddlerhood or later, but a new study suggests infants with symptoms of the developmental disorder might benefit from therapy from as early as six months.

Knatalye and Adeline born with an everlasting bond

Knatalye Hope and Adeline Faith are a lot like any other identical twin girls, but there is one dramatic difference: they're joined at the chest and shares several internal organs.

The question this dad wishes he'd asked his wife

I should have seen that my wife wasn't the same person I'd fallen in love with, but we were both too focused on simply trying to get by.

Why we should talk about the deaths of the Hunt children

The deaths are too horrible even to think about. Yet we owe it to the children - Fletcher, Mia and Phoebe Hunt - to think long and hard about it all.

Baby dies of meningococcal weeks after vaccine application denied

A six-month-old girl has died from meningococcal disease just weeks after an application for government funding of a vaccine for the most deadly strain of the virus was rejected.

Finding the right balance when playing with your kids

Being too involved in our children?s play and not allowing our kids enough free time for unstructured activities can mean our kids miss out on the value that play offers.

Creative DIY light shades

The Pop Light light shade comes in a flat pack already made - it's up to you to design it as you'd like.

The battle of iParenting versus imagination

Have we forgotten how to be imaginative, resourceful parents?

Why movement is so important for your baby's growth

Letting your child move as much as possible in the early years ? using all senses, engaging in the real world, preferably outside ? will help them grow up healthier, smarter, calmer and stronger.

Download now: Essential Kids Activity Finder app

Got bored kids? Quickly find the best activities for kids wherever you are in Australia with the Essential Kids app.

 
Advertisement
 
Advertisement
 
 
 

What's hot on EB

Special offer: The Baby & Toddler Show 2014

At The Baby & Toddler Show, you?ll find everything you need to get ready for your new arrival and guide you through the early weeks and years of parenting.

Losing yourself to motherhood

While watching your baby grow into a unique little person is exciting and wondrous, the intensity of meeting everyone else?s needs can ever so sneakily overtake your own needs for self-care.

Tearing during delivery: the facts

Almost all women will experience bruising, grazing or tearing after a vaginal birth. Depending on the degree of tearing, there are various treatments available.

6 tips for a day out with a baby and toddler

Outings can be lots of fun with the kids, but there are inevitable challenges. Here's some information about days out to help you be a little more prepared.

Why I invited a dozen people to watch my son's birth

I sent invitations on burgundy scrapbooking paper stamped with a field of poppies, and told each person why I wanted him or her there. I warned that there would be nudity.

Getting labour started: tips for a natural induction

When your baby?s due date comes and goes without so much as a pop - let alone a bang - it can be disheartening. Mums and a doula share their stories of natural inductions.

7 mistakes old hands make with new babies

As I sat across the table from my friend ? me, a seasoned mother of three; her, a brand new mum ? I thought of all the mistakes an old-hand parent can make when visiting a newborn baby.

That's my boy: a dad's diary of the first 4 months

Unbearable anxiety, unspeakable joy, constant exhaustion and bouts of frustration ... The many shocks of first-time fatherhood resound in a dad's diary of his son's early months.

One of the most important things a new mum can do

Finances may not be as cute as a newborn, but with many women?s working arrangements changing post-baby, monetary matters need attention too.

Dying mum saves baby with last breath

Dying from a gunshot wound, Jessica Arrendale used the last of her energy to hide her baby from her killer.

Personalised baby gifts

We've scoured the internet to find gorgeous personalised keepsakes and nursery decor to record baby name and dates. They make great gifts for christenings, name days and birthdays! (All prices in AU.)

 

Reader offer

2 FOR 1 TICKET OFFER

For Shopping, For Advice, For Baby & You. Enjoy a special day out with fabulous shopping from over 200 brands, leading parenting experts offering advice on a range of topics, and amazing children?s entertainment

 
Advertisement
 
 
Essential Baby and Essential Kids is the place to find parenting information and parenting support relating to conception, pregnancy, birth, babies, toddlers, kids, maternity, family budgeting, family travel, nutrition and wellbeing, family entertainment, kids entertainment, tips for the family home, child-friendly recipes and parenting. Try our pregnancy due date calculator to determine your due date, or our ovulation calculator to predict ovulation and your fertile period. Our pregnancy week by week guide shows your baby's stages of development. Access our very active mum's discussion groups in the Essential Baby forums or the Essential Kids forums to talk to mums about conception, pregnancy, birth, babies, toddlers, kids and parenting lifestyle. Essential Baby also offers a baby names database of more than 22,000 baby names, popular baby names, boys' names, girls' names and baby names advice in our baby names forum. Essential Kids features a range of free printable worksheets for kids from preschool years through to primary school years. For the latest baby clothes, maternity clothes, maternity accessories, toddler products, kids toys and kids clothing, breastfeeding and other parenting resources, check out Essential Baby and Essential Kids.