There were some blue, red and green files in a box.
111 of the files were red. The ratio of the number of blue files to the number of green files was 3 : 7. There were 342 fewer red files than green files.
- Find the ratio of the number of blue files to the number of red files to the number of green files in the box.
- How many green files were there?
Red |
Blue |
Green |
Total |
1 |
10 |
11 |
|
3 |
7 |
|
1 u |
3 u |
7 u |
11 u |
(a)
Blue : Red : Green
3 : 1 : 7
(b)
Number of fewer red files than green files
= 7 u - 1 u
= 6 u
6 u = 342
1 u = 342 ÷ 6 = 57
Number of green files
= 7 u
= 7 x 57
= 399
Answer(s): (a) 3 : 1 : 7; (b) 399