In March, Emily and Ivan had stickers in the ratio 5 : 4. In April, each of them gave away the same number of stickers. Emily then had five times as many stickers as Ivan.

1. Find the ratio of the number of stickers Ivan had in March to the number of stickers he had in April.
2. Find the ratio of the total number of stickers both had in March to the total number of stickers both had in April.

	Emily	Ivan	Difference
Before	5x4 = 20 u	4x4 = 16 u	1x4 = 4 u
Change	- 15 u	- 15 u
After	5x1 = 5 u	1x1 = 1 u	4x1 = 4 u

(a)
Since Emily and Ivan gave away the same number of stickers, the difference in the number of stickers between Emily and Ivan at first and in the end remains the same.

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

Ivan's stickers in March : Ivan's stickers in April
16 : 1

(b)
Total number of stickers in March
= 20 u + 16 u
= 36 u

Total number of stickers in April
= 5 u + 1 u
= 6 u

Total stickers in March : Total stickers in April
36 : 6 _(÷6)
6 : 1 

Answer(s): (a) 16 : 1; (b) 6 : 1