Charlie, Peter and Bobby have some stickers. The ratios of their stickers are as follows:

Charlie : (Charlie + Peter + Bobby) = 1 : 3
Peter : (Charlie + Bobby) = 1 : 3

Bobby has 6 stickers more than Peter. In the end, Bobby gives away all he has to Peter and Charlie so that both Peter and Charlie end up with the same number of stickers, how many stickers has Peter received from Bobby?

Peter	Bobby	Charlie	Total
2x4		1x4	3x4
1x3	3x3		4x3
3 u	5 u	4 u	12 u

The total number of stickers is repeated.  Make the total number of stickers the same.  LCM of 3 and 4 is 12.

Number of stickers that Bobby has more than Peter
= 5 u - 3 u
= 2 u

2 u = 6

1 u = 6 ÷ 2 = 3

	Peter	Bobby	Charlie
Before	3 u	5 u	4 u
Change	+ 3 u	- 5 u	+ 2 u
After	6 u	0 u	6 u

Number of stickers that Peter has received from Bobby
= 6 u - 3 u 
= 3 u
= 3 x 3
= 9

Answer(s): 9