In April, Pamela and Ethan had erasers in the ratio 9 : 7. In May, each of them gave away the same number of erasers. Pamela then had five times as many erasers as Ethan.

1. Find the ratio of the number of erasers Ethan had in April to the number of erasers he had in May.
2. Find the ratio of the total number of erasers both had in April to the total number of erasers both had in May.

	Pamela	Ethan	Difference
Before	9x2 = 18 u	7x2 = 14 u	2x2 = 4 u
Change	- 13 u	- 13 u
After	5x1 = 5 u	1x1 = 1 u	4x1 = 4 u

(a)
Since Pamela and Ethan gave away the same number of erasers, the difference in the number of erasers between Pamela and Ethan at first and in the end remains the same.

Make the difference in the number of erasers at first and in the end the same. LCM of 2 and 4 is 4.

Ethan's erasers in April : Ethan's erasers in May
14 : 1

(b)
Total number of erasers in April
= 18 u + 14 u
= 32 u

Total number of erasers in May
= 5 u + 1 u
= 6 u

Total erasers in April : Total erasers in May
32 : 6 _(÷2)
16 : 3 

Answer(s): (a) 14 : 1; (b) 16 : 3