PSLE Emma had a basket of white marbles and green marbles in the ratio 13 : 9. She removed an equal number of white marbles and green marbles from the basket. The ratio of the number of white marbles and green marbles left in the basket became 8 : 3. What percentage of the marbles were left in the basket?
|
White marbles |
Green marbles |
Difference |
Total |
Before |
13x5 = 65 u |
9x5 = 45 u |
4x5 = 20 u |
22x5 = 110 u |
Change |
- 33 u |
- 33 u |
|
|
After |
8x4 = 32 u |
3x4 = 12 u |
5x4 = 20 u |
11x4 = 44 u |
When Emma removed an equal number of white marbles and green marbles, the difference between the number of white marbles and green marbles at first and in the end remains the same.
LCM of 4 and 5 is 20.
Percentage of the marbles left in the basket
=
44110 x 100%
= 25 x 100%
= 40%
Answer: 40%