There were 188 pink, grey and yellow staplers in a box. 23 yellow staplers were removed from the box and the ratio of the number of pink staplers to the number of grey staplers to the number of yellow staplers became 3 : 5 : 7. Then some brown staplers were added and the ratio of the number of yellow staplers to the number of brown staplers was 7 : 4.

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

	Pink	Grey	Yellow	Brown	Total
Before	3 u	5 u	7 u + 23	0	188
Change 1	No change	No change	- 23		- 23
After 1	3 u	5 u	7 u		165
Change 2	No change	No change	No change	+ 4 u
After 2	3 u	5 u	7 u	4 u

(a)
Total number of staplers at first
= 3 u + 5 u + 7 u + 23
= 15 u + 23

15 u + 23 = 188
15 u = 188 - 23
15 u = 165

1 u = 165 ÷ 15 = 11

Number of pink staplers at first
= 3 u
= 3 x 11
= 33

Number of grey staplers at first
= 5 u
= 5 x 11
= 55

Number of yellow staplers at first
= 7 u + 23
= 7 x 11 + 23
= 100 

At first
Pink staplers : Grey staplers : Yellow staplers
33 : 55 : 100

(b)
Total number of staplers in the box in the end
= 3 u + 5 u + 7 u + 4 u
= 19 u
= 209

Answer(s): (a) 33 : 55 : 100; (b) 209