11 Plus Exams Forum

Hi My daughter had this question on a practise paper:

Peter, Alex and Michelle share sweets in a bag in the ratio 4:3:2 Michelle receives 8 How many sweets are there in the bag at the start?

I was able to do it by looking at Michelle at the beginning and seeing what I needed to do to 2 to make it 8 i.e. times by 4 so times all the rest of the number by 4 then adding up the totals which came to the correct number 36. This is a long process though and in the back of the book they add 4+3+2 together then times it by 4. Why do you times it by 4?

Thank-you!

there must be a multiple of 4+3+2=9 in the bag,

you know that Michelle gets 8 which is 4 times her share of the 9

so presume you then multiply 9*4 and get 36

angelfire777 wrote:Hi My daughter had this question on a practise paper:

Peter, Alex and Michelle share sweets in a bag in the ratio 4:3:2 Michelle receives 8 How many sweets are there in the bag at the start?

I was able to do it by looking at Michelle at the beginning and seeing what I needed to do to 2 to make it 8 i.e. times by 4 so times all the rest of the number by 4 then adding up the totals which came to the correct number 36. This is a long process though and in the back of the book they add 4+3+2 together then times it by 4. Why do you times it by 4?

Thank-you!

I think that you've already answered your own question haven't you?

You already worked out that you need to multiply each ratio by 4 and then total them up. It seems that all the book answer has done is to simplify the sum slightly by taking out the common factor of 4.

i.e. 4 * 4 + 4 * 3 + 4 * 2 = 4 (4 + 3 + 2)