puzzle help

11 Plus Maths – Preparation and Information

Moderators: Section Moderators, Forum Moderators

Post Reply
11 Plus Mocks - Practise the real exam experience - Book Now
guest574

puzzle help

Post by guest574 »

My brother, sister and I are given a bag of sweets. My brother
has first pick and greedily eats two-thirds of them. He hands
the bag to my sister who eats three-quarters of the remaining
sweets. There are just 6 sweets left for me. How many sweets
did the bag contain to begin with?
Guest

Post by Guest »

72.

If you have 6 and that was 1/4 of what was remaining after your brother ate his, then he handed over 24. As he's already eaten 2/3 of them it means that he must have had 72 to start with ie 24 x 3.
Hope this makes sense!
guest574

Post by guest574 »

No really, can you please explain properly.
Guest

Post by Guest »

I'll try again.

You have 6 sweets
Your sister ate 3/4 ie 6 x 3 = 18
Total between you and your sister = 18 + 6 = 24
Your brother ate 2/3 of the original and gave you both 1/3
If 1/3 = 24 then his 2/3 must be 24 x 2 = 48
Total number of sweets was 24 + 48 = 72

If this doesn't make sense then no doubt someone else can explain better.
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Post by yoyo123 »

I find diagrams really useful with questions like this work backwards from what youhave (ie 6 sweets)
Another parent

Post by Another parent »

I thought you did explain it properly. Well done and thanks from me.
Guest

Post by Guest »

It might help if you think of what's left each time rather than what's been eaten. If brother eats 2/3 he leaves 1/3. Sister leaves 1/4 of 1/3 = 6. So, if 6 = 1/12 of what they started with, they must have had 12 x 6 = 72 at the outset.

Personally, I would have scoffed the lot and there would have been no problem! :D
Post Reply