PSLE A box contained black marbles and silver marbles. 40% of the marbles were silver. After some blue marbles were added to the box, 6% of the marbles were silver. What percentage of the marbles in the box were blue?
|
Silver |
Black |
Blue |
Total |
Before |
2 u |
3 u |
|
5 u |
Change |
|
|
+ ? |
|
After |
6% |
9% |
|
100% |
40% =
40100 =
25 The number of silver marbles remains unchanged.
2 u → 6%
1 u → 6% ÷ 2 = 3%
3 u → 3 x 3 = 9%
Percentage of the marbles in the box that were blue
= 100% - 6% - 9%
= 85%
Answer(s): 85%