There were 219 white, red and pink staplers in a box. 10 pink staplers were removed from the box and the ratio of the number of white staplers to the number of red staplers to the number of pink staplers became 4 : 2 : 5. Then some yellow staplers were added and the ratio of the number of pink staplers to the number of yellow staplers was 5 : 7.

1. What was the ratio of the number of white staplers to the number of red staplers to the number of pink staplers at first?
2. How many staplers were in the box in the end?

	White	Red	Pink	Yellow	Total
Before	4 u	2 u	5 u + 10	0	219
Change 1	No change	No change	- 10		- 10
After 1	4 u	2 u	5 u		209
Change 2	No change	No change	No change	+ 7 u
After 2	4 u	2 u	5 u	7 u

(a)
Total number of staplers at first
= 4 u + 2 u + 5 u + 10
= 11 u + 10

11 u + 10 = 219
11 u = 219 - 10
11 u = 209

1 u = 209 ÷ 11 = 19

Number of white staplers at first
= 4 u
= 4 x 19
= 76

Number of red staplers at first
= 2 u
= 2 x 19
= 38

Number of pink staplers at first
= 5 u + 10
= 5 x 19 + 10
= 105 

At first
White staplers : Red staplers : Pink staplers
76 : 38 : 105

(b)
Total number of staplers in the box in the end
= 4 u + 2 u + 5 u + 7 u
= 18 u
= 342

Answer(s): (a) 76 : 38 : 105; (b) 342