There were some purple, grey and brown files in a box.
112 of the files were grey. The ratio of the number of purple files to the number of brown files was 4 : 7. There were 276 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 |
1 |
11 |
12 |
|
4 |
7 |
|
1 u |
4 u |
7 u |
12 u |
(a)
Purple : Grey : Brown
4 : 1 : 7
(b)
Number of fewer grey files than brown files
= 7 u - 1 u
= 6 u
6 u = 276
1 u = 276 ÷ 6 = 46
Number of brown files
= 7 u
= 7 x 46
= 322
Answer(s): (a) 4 : 1 : 7; (b) 322