PSLE A box contained grey marbles and gold marbles. 60% of the marbles were gold. After some white marbles were added to the box, 15% of the marbles were gold. What percentage of the marbles in the box were white?
|
Gold |
Grey |
White |
Total |
Before |
3 u |
2 u |
|
5 u |
Change |
|
|
+ ? |
|
After |
15% |
10% |
|
100% |
60% =
60100 =
35 The number of gold marbles remains unchanged.
3 u → 15%
1 u → 15% ÷ 3 = 5%
2 u → 2 x 5 = 10%
Percentage of the marbles in the box that were white
= 100% - 15% - 10%
= 75%
Answer(s): 75%