There were some purple, grey and brown files in a box.
211 of the files were grey. The ratio of the number of purple files to the number of brown files was 4 : 5. There were 318 fewer grey files than brown files.
- Find the ratio of the number of purple files to the number of grey files to the number of brown files in the box.
- How many brown files 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 files than brown files
= 5 u - 2 u
= 3 u
3 u = 318
1 u = 318 ÷ 3 = 106
Number of brown files
= 5 u
= 5 x 106
= 530
Answer(s): (a) 4 : 2 : 5; (b) 530