In February, Irene and Perry had coins in the ratio 10 : 9. In March, each of them gave away the same number of coins. Irene then had five times as many coins as Perry.

1. Find the ratio of the number of coins Perry had in February to the number of coins he had in March.
2. Find the ratio of the total number of coins both had in February to the total number of coins both had in March.

	Irene	Perry	Difference
Before	10x4 = 40 u	9x4 = 36 u	1x4 = 4 u
Change	- 35 u	- 35 u
After	5x1 = 5 u	1x1 = 1 u	4x1 = 4 u

(a)
Since Irene and Perry gave away the same number of coins, the difference in the number of coins between Irene and Perry at first and in the end remains the same.

Make the difference in the number of coins at first and in the end the same. LCM of 1 and 4 is 4.

Perry's coins in February : Perry's coins in March
36 : 1

(b)
Total number of coins in February
= 40 u + 36 u
= 76 u

Total number of coins in March
= 5 u + 1 u
= 6 u

Total coins in February : Total coins in March
76 : 6 _(÷2)
38 : 3 

Answer(s): (a) 36 : 1; (b) 38 : 3