There were 98 grey, green and brown markers in a box. 8 brown markers were removed from the box and the ratio of the number of grey markers to the number of green markers to the number of brown markers became 3 : 2 : 5. Then some yellow markers were added and the ratio of the number of brown markers to the number of yellow markers was 5 : 9.
- What was the ratio of the number of grey markers to the number of green markers to the number of brown markers at first?
- How many markers were in the box in the end?
|
Grey |
Green |
Brown |
Yellow |
Total |
Before |
3 u |
2 u |
5 u + 8 |
0 |
98 |
Change 1 |
No change |
No change |
- 8 |
|
- 8 |
After 1 |
3 u |
2 u |
5 u |
|
90 |
Change 2 |
No change |
No change |
No change |
+ 9 u |
|
After 2 |
3 u |
2 u |
5 u |
9 u |
|
(a)
Total number of markers at first
= 3 u + 2 u + 5 u + 8
= 10 u + 8
10 u + 8 = 98
10 u = 98 - 8
10 u = 90
1 u = 90 ÷ 10 = 9
Number of grey markers at first
= 3 u
= 3 x 9
= 27
Number of green markers at first
= 2 u
= 2 x 9
= 18
Number of brown markers at first
= 5 u + 8
= 5 x 9 + 8
= 53
At first
Grey markers : Green markers : Brown markers
27 : 18 : 53
(b)
Total number of markers in the box in the end
= 3 u + 2 u + 5 u + 9 u
= 19 u
= 171
Answer(s): (a) 27 : 18 : 53; (b) 171