PSLE A box contained yellow marbles and silver marbles. 60% of the marbles were silver. After some grey marbles were added to the box, 51% of the marbles were silver. What percentage of the marbles in the box were grey?
|
Silver |
Yellow |
Grey |
Total |
Before |
3 u |
2 u |
|
5 u |
Change |
|
|
+ ? |
|
After |
51% |
34% |
|
100% |
60% =
60100 =
35 The number of silver marbles remains unchanged.
3 u → 51%
1 u → 51% ÷ 3 = 17%
2 u → 2 x 17 = 34%
Percentage of the marbles in the box that were grey
= 100% - 51% - 34%
= 15%
Answer(s): 15%