David and Zeph shared some stickers in the ratio of 3 : 8. After both each gave away 49 stickers to their sister, the ratio of the number of stickers David had to the total number of stickers left was 1 : 6. How many stickers did the two boys have at first?

	David	Zeph	Difference
Before	3x4 = 12 u	8x4 = 32 u	5x4 = 20 u
Change	- 49	- 49
After	1x5 = 5 u	5x5 = 25 u	4x5 = 20 u

Number of stickers that David and Zeph each gave to their sister is the same.

The difference in the number of stickers at first and in the end between David and Zeph remains unchanged.  Make the difference in the number of stickers the same.  LCM of 5 and 4 is 20.

Number of stickers that David gave to their sister
= 12 u - 5 u
= 7 u

7 u = 49

1 u = 49 ÷ 7 = 7

Number of stickers that the two boys had at first
= 12 u + 32 u
= 44 u
= 44 x 7
= 308

Answer(s): 308