There were 88 black, green and brown staplers in a box. 8 brown staplers were removed from the box and the ratio of the number of black staplers to the number of green staplers to the number of brown staplers became 3 : 4 : 9. Then some gold staplers were added and the ratio of the number of brown staplers to the number of gold staplers was 9 : 6.
- What was the ratio of the number of black staplers to the number of green staplers to the number of brown staplers at first?
- How many staplers were in the box in the end?
|
Black |
Green |
Brown |
Gold |
Total |
Before |
3 u |
4 u |
9 u + 8 |
0 |
88 |
Change 1 |
No change |
No change |
- 8 |
|
- 8 |
After 1 |
3 u |
4 u |
9 u |
|
80 |
Change 2 |
No change |
No change |
No change |
+ 6 u |
|
After 2 |
3 u |
4 u |
9 u |
6 u |
|
(a)
Total number of staplers at first
= 3 u + 4 u + 9 u + 8
= 16 u + 8
16 u + 8 = 88
16 u = 88 - 8
16 u = 80
1 u = 80 ÷ 16 = 5
Number of black staplers at first
= 3 u
= 3 x 5
= 15
Number of green staplers at first
= 4 u
= 4 x 5
= 20
Number of brown staplers at first
= 9 u + 8
= 9 x 5 + 8
= 53
At first
Black staplers : Green staplers : Brown staplers
15 : 20 : 53
(b)
Total number of staplers in the box in the end
= 3 u + 4 u + 9 u + 6 u
= 22 u
= 110
Answer(s): (a) 15 : 20 : 53; (b) 110