PSLE A box contained grey marbles and white marbles. 60% of the marbles were white. After some blue marbles were added to the box, 45% of the marbles were white. What percentage of the marbles in the box were blue?
|
White |
Grey |
Blue |
Total |
Before |
3 u |
2 u |
|
5 u |
Change |
|
|
+ ? |
|
After |
45% |
30% |
|
100% |
60% =
60100 =
35 The number of white marbles remains unchanged.
3 u → 45%
1 u → 45% ÷ 3 = 15%
2 u → 2 x 15 = 30%
Percentage of the marbles in the box that were blue
= 100% - 45% - 30%
= 25%
Answer(s): 25%