Eric and Asher shared some erasers in the ratio of 5 : 8. After both each gave away 4 erasers to their sister, the ratio of the number of erasers Eric had to the total number of erasers left was 1 : 3. How many erasers did the two boys have at first?

	Eric	Asher	Difference
Before	5x1 = 5 u	8x1 = 8 u	3x1 = 3 u
Change	- 4	- 4
After	1x3 = 3 u	2x3 = 6 u	1x3 = 3 u

Number of erasers that Eric and Asher each gave to their sister is the same.

The difference in the number of erasers at first and in the end between Eric and Asher remains unchanged.  Make the difference in the number of erasers the same.  LCM of 3 and 1 is 3.

Number of erasers that Eric gave to their sister
= 5 u - 3 u
= 2 u

2 u = 4

1 u = 4 ÷ 2 = 2

Number of erasers that the two boys had at first
= 5 u + 8 u
= 13 u
= 13 x 2
= 26

Answer(s): 26