Oliver and Glen shared some stickers in the ratio of 5 : 7. After both each gave away 12 stickers to their brother, the ratio of the number of stickers Oliver had to the total number of stickers left was 1 : 3. How many stickers did the two boys have in the end?

	Oliver	Glen	Difference
Before	5x1 = 5 u	7x1 = 7 u	2x1 = 2 u
Change	- 12	- 12
After	1x2 = 2 u	2x2 = 4 u	1x2 = 2 u

Number of stickers that Oliver and Glen each gave to their brother is the same.

The difference in the number of stickers at first and in the end between Oliver and Glen remains unchanged.  Make the difference in the number of stickers the same.  LCM of 2 and 1 is 2.

Number of stickers that Oliver gave to their brother
= 5 u - 2 u
= 3 u

3 u = 12

1 u = 12 ÷ 3 = 4

Number of stickers that the two boys had in the end
= 2 u + 4 u
= 6 u
= 6 x 4
= 24

Answer(s): 24