There were some blue, red and green pens in a box.
211 of the pens were red. The ratio of the number of blue pens to the number of green pens was 4 : 5. There were 315 fewer red pens than green pens.
- Find the ratio of the number of blue pens to the number of red pens to the number of green pens in the box.
- How many green pens were there?
Red |
Blue |
Green |
Total |
2 |
9 |
11 |
|
4 |
5 |
|
2 u |
4 u |
5 u |
11 u |
(a)
Blue : Red : Green
4 : 2 : 5
(b)
Number of fewer red pens than green pens
= 5 u - 2 u
= 3 u
3 u = 315
1 u = 315 ÷ 3 = 105
Number of green pens
= 5 u
= 5 x 105
= 525
Answer(s): (a) 4 : 2 : 5; (b) 525