There were some purple, grey and brown notebooks in a box.
211 of the notebooks were grey. The ratio of the number of purple notebooks to the number of brown notebooks was 4 : 5. There were 255 fewer grey notebooks than brown notebooks.
- Find the ratio of the number of purple notebooks to the number of grey notebooks to the number of brown notebooks in the box.
- How many brown notebooks were there?
Grey |
Purple |
Brown |
Total |
2 |
9 |
11 |
|
4 |
5 |
|
2 u |
4 u |
5 u |
11 u |
(a)
Purple : Grey : Brown
4 : 2 : 5
(b)
Number of fewer grey notebooks than brown notebooks
= 5 u - 2 u
= 3 u
3 u = 255
1 u = 255 ÷ 3 = 85
Number of brown notebooks
= 5 u
= 5 x 85
= 425
Answer(s): (a) 4 : 2 : 5; (b) 425