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puzzle help
Posted: Thu Nov 15, 2007 4:17 pm
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?
Posted: Thu Nov 15, 2007 4:41 pm
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!
Posted: Thu Nov 15, 2007 5:12 pm
by guest574
No really, can you please explain properly.
Posted: Thu Nov 15, 2007 5:23 pm
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.
Posted: Thu Nov 15, 2007 6:26 pm
by yoyo123
I find diagrams really useful with questions like this work backwards from what youhave (ie 6 sweets)
Posted: Thu Nov 15, 2007 7:10 pm
by Another parent
I thought you did explain it properly. Well done and thanks from me.
Posted: Tue Nov 20, 2007 9:29 pm
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!
