There were 92 green, grey and white markers in a box. 8 white markers were removed from the box and the ratio of the number of green markers to the number of grey markers to the number of white markers became 4 : 3 : 5. Then some gold markers were added and the ratio of the number of white markers to the number of gold markers was 5 : 4.
- What was the ratio of the number of green markers to the number of grey markers to the number of white markers at first?
- How many markers were in the box in the end?
|
Green |
Grey |
White |
Gold |
Total |
Before |
4 u |
3 u |
5 u + 8 |
0 |
92 |
Change 1 |
No change |
No change |
- 8 |
|
- 8 |
After 1 |
4 u |
3 u |
5 u |
|
84 |
Change 2 |
No change |
No change |
No change |
+ 4 u |
|
After 2 |
4 u |
3 u |
5 u |
4 u |
|
(a)
Total number of markers at first
= 4 u + 3 u + 5 u + 8
= 12 u + 8
12 u + 8 = 92
12 u = 92 - 8
12 u = 84
1 u = 84 ÷ 12 = 7
Number of green markers at first
= 4 u
= 4 x 7
= 28
Number of grey markers at first
= 3 u
= 3 x 7
= 21
Number of white markers at first
= 5 u + 8
= 5 x 7 + 8
= 43
At first
Green markers : Grey markers : White markers
28 : 21 : 43
(b)
Total number of markers in the box in the end
= 4 u + 3 u + 5 u + 4 u
= 16 u
= 112
Answer(s): (a) 28 : 21 : 43; (b) 112