PSLE A box contained red balls and green balls. 40% of the balls were green. After some gold balls were added to the box, 38% of the balls were green. What percentage of the balls in the box were gold?
|
Green |
Red |
Gold |
Total |
Before |
2 u |
3 u |
|
5 u |
Change |
|
|
+ ? |
|
After |
38% |
57% |
|
100% |
40% =
40100 =
25 The number of green balls remains unchanged.
2 u → 38%
1 u → 38% ÷ 2 = 19%
3 u → 3 x 19 = 57%
Percentage of the balls in the box that were gold
= 100% - 38% - 57%
= 5%
Answer(s): 5%