In February, Min and Will had stamps in the ratio 11 : 9. In March, each of them gave away the same number of stamps. Min then had five times as many stamps as Will.

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

	Min	Will	Difference
Before	11x2 = 22 u	9x2 = 18 u	2x2 = 4 u
Change	- 17 u	- 17 u
After	5x1 = 5 u	1x1 = 1 u	4x1 = 4 u

(a)
Since Min and Will gave away the same number of stamps, the difference in the number of stamps between Min and Will at first and in the end remains the same.

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

Will's stamps in February : Will's stamps in March
18 : 1

(b)
Total number of stamps in February
= 22 u + 18 u
= 40 u

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

Total stamps in February : Total stamps in March
40 : 6 _(÷2)
20 : 3 

Answer(s): (a) 18 : 1; (b) 20 : 3