Betty had some brown stamps and pink stamps in 2 bags. In Bag K, the ratio of the number of brown stamps to pink stamps was 8 : 7. In Bag L, the number of brown stamps was 2 times the number of pink stamps. Betty transferred ⁴₇ of the pink stamps from Bag K to Bag L. The number of stamps in Bag K became 33 and the ratio of the number of brown stamps to pink stamps in Bag L became 4 : 5.

1. How many pink stamps were transferred from Bag K to Bag L?
2. What was the number of stamps in Bag L after the transfer?

	Bag K		Bag L
	Brown	Pink	Brown	Pink
Comparing brown stamps and pink stamps at first	8 u	7 u	2x2 = 4 p	1x2 = 2 p
Before		7 u
Change		- 4 u		+ 4 u
After		3 u
Comparing brown stamps and pink stamps in the end	8 u	3 u	4 p	5 p

(a)
Total number of stamps in the end for Bag K
= 8 u + 3 u
= 11 u

11 u = 33

1 u = 33 ÷ 11 = 3

Number of pink stamps that were transferred from Bag K to Bag L
= 4 u
= 4 x 3
= 12

(b)
The number of brown stamps in Bag L remains unchanged.  Make the number of brown stamps in Bag L the same.  LCM of 2 and 4 is 4. 

Increase in the number of pink stamps in Bag L
= 5 p - 2 p
= 3 p

3 p = 4 u
3 p = 12

1 p = 12 ÷ 3 = 4

Number of stamps in Bag L in the end
= 4 p + 5 p
= 9 p
= 9 x 4
= 36

Answer(s): (a) 12; (b) 36