Warren and George shared some coins in the ratio of 3 : 7. After both each gave away 45 coins to their sister, the ratio of the number of coins Warren had to the total number of coins left was 1 : 5. How many coins did the two boys have in the end?

	Warren	George	Difference
Before	3x3 = 9 u	7x3 = 21 u	4x3 = 12 u
Change	- 45	- 45
After	1x4 = 4 u	4x4 = 16 u	3x4 = 12 u

Number of coins that Warren and George each gave to their sister is the same.

The difference in the number of coins at first and in the end between Warren and George remains unchanged.  Make the difference in the number of coins the same.  LCM of 4 and 3 is 12.

Number of coins that Warren gave to their sister
= 9 u - 4 u
= 5 u

5 u = 45

1 u = 45 ÷ 5 = 9

Number of coins that the two boys had in the end
= 4 u + 16 u
= 20 u
= 20 x 9
= 180

Answer(s): 180