There were some brown, black and gold notebooks in a box.
110 of the notebooks were black. The ratio of the number of brown notebooks to the number of gold notebooks was 4 : 5. There were 252 fewer black notebooks than gold notebooks.
- Find the ratio of the number of brown notebooks to the number of black notebooks to the number of gold notebooks in the box.
- How many gold notebooks were there?
Black |
Brown |
Gold |
Total |
1 |
9 |
10 |
|
4 |
5 |
|
1 u |
4 u |
5 u |
10 u |
(a)
Brown : Black : Gold
4 : 1 : 5
(b)
Number of fewer black notebooks than gold notebooks
= 5 u - 1 u
= 4 u
4 u = 252
1 u = 252 ÷ 4 = 63
Number of gold notebooks
= 5 u
= 5 x 63
= 315
Answer(s): (a) 4 : 1 : 5; (b) 315