In March, Betty and Albert had erasers in the ratio 2 : 1. In April, each of them gave away the same number of erasers. Betty then had five times as many erasers as Albert.

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

	Betty	Albert	Difference
Before	2x4 = 8 u	1x4 = 4 u	1x4 = 4 u
Change	- 3 u	- 3 u
After	5x1 = 5 u	1x1 = 1 u	4x1 = 4 u

(a)
Since Betty and Albert gave away the same number of erasers, the difference in the number of erasers between Betty and Albert 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 1 and 4 is 4.

Albert's erasers in March : Albert's erasers in April
4 : 1

(b)
Total number of erasers in March
= 8 u + 4 u
= 12 u

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

Total erasers in March : Total erasers in April
12 : 6 _(÷6)
2 : 1 

Answer(s): (a) 4 : 1; (b) 2 : 1