PSLE Tiffany had a basket of black marbles and silver marbles in the ratio 16 : 9. She removed an equal number of black marbles and silver marbles from the basket. The ratio of the number of black marbles and silver marbles left in the basket became 10 : 3. What percentage of the marbles were left in the basket?
|
Black marbles |
Silver marbles |
Difference |
Total |
Before |
16x1 = 16 u |
9x1 = 9 u |
7x1 = 7 u |
25x1 = 25 u |
Change |
- 6 u |
- 6 u |
|
|
After |
10x1 = 10 u |
3x1 = 3 u |
7x1 = 7 u |
13x1 = 13 u |
When Tiffany removed an equal number of black marbles and silver marbles, the difference between the number of black marbles and silver marbles at first and in the end remains the same.
LCM of 7 and 7 is 7.
Percentage of the marbles left in the basket
=
1325 x 100%
= 1325 x 100%
= 52%
Answer: 52%