There were 117 red, brown and yellow staplers in a box. 7 yellow staplers were removed from the box and the ratio of the number of red staplers to the number of brown staplers to the number of yellow staplers became 2 : 4 : 5. Then some gold staplers were added and the ratio of the number of yellow staplers to the number of gold staplers was 5 : 3.

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

	Red	Brown	Yellow	Gold	Total
Before	2 u	4 u	5 u + 7	0	117
Change 1	No change	No change	- 7		- 7
After 1	2 u	4 u	5 u		110
Change 2	No change	No change	No change	+ 3 u
After 2	2 u	4 u	5 u	3 u

(a)
Total number of staplers at first
= 2 u + 4 u + 5 u + 7
= 11 u + 7

11 u + 7 = 117
11 u = 117 - 7
11 u = 110

1 u = 110 ÷ 11 = 10

Number of red staplers at first
= 2 u
= 2 x 10
= 20

Number of brown staplers at first
= 4 u
= 4 x 10
= 40

Number of yellow staplers at first
= 5 u + 7
= 5 x 10 + 7
= 57 

At first
Red staplers : Brown staplers : Yellow staplers
20 : 40 : 57

(b)
Total number of staplers in the box in the end
= 2 u + 4 u + 5 u + 3 u
= 14 u
= 140

Answer(s): (a) 20 : 40 : 57; (b) 140