There were 109 pink, blue and red markers in a box. 19 red markers were removed from the box and the ratio of the number of pink markers to the number of blue markers to the number of red markers became 2 : 5 : 3. Then some green markers were added and the ratio of the number of red markers to the number of green markers was 3 : 5.
- What was the ratio of the number of pink markers to the number of blue markers to the number of red markers at first?
- How many markers were in the box in the end?
|
Pink |
Blue |
Red |
Green |
Total |
Before |
2 u |
5 u |
3 u + 19 |
0 |
109 |
Change 1 |
No change |
No change |
- 19 |
|
- 19 |
After 1 |
2 u |
5 u |
3 u |
|
90 |
Change 2 |
No change |
No change |
No change |
+ 5 u |
|
After 2 |
2 u |
5 u |
3 u |
5 u |
|
(a)
Total number of markers at first
= 2 u + 5 u + 3 u + 19
= 10 u + 19
10 u + 19 = 109
10 u = 109 - 19
10 u = 90
1 u = 90 ÷ 10 = 9
Number of pink markers at first
= 2 u
= 2 x 9
= 18
Number of blue markers at first
= 5 u
= 5 x 9
= 45
Number of red markers at first
= 3 u + 19
= 3 x 9 + 19
= 46
At first
Pink markers : Blue markers : Red markers
18 : 45 : 46
(b)
Total number of markers in the box in the end
= 2 u + 5 u + 3 u + 5 u
= 15 u
= 135
Answer(s): (a) 18 : 45 : 46; (b) 135