PSLE A box contained green balls and white balls. 30% of the balls were white. After some yellow balls were added to the box, 24% of the balls were white. What percentage of the balls in the box were yellow?
|
White |
Green |
Yellow |
Total |
Before |
3 u |
7 u |
|
10 u |
Change |
|
|
+ ? |
|
After |
24% |
56% |
|
100% |
30% =
30100 =
310 The number of white balls remains unchanged.
3 u → 24%
1 u → 24% ÷ 3 = 8%
7 u → 7 x 8 = 56%
Percentage of the balls in the box that were yellow
= 100% - 24% - 56%
= 20%
Answer(s): 20%