PSLE Abi had a box of grey marbles and silver marbles in the ratio 17 : 8. She removed an equal number of grey marbles and silver marbles from the box. The ratio of the number of grey marbles and silver marbles left in the box became 10 : 1. What percentage of the marbles were left in the box?
|
Grey marbles |
Silver marbles |
Difference |
Total |
Before |
17x1 = 17 u |
8x1 = 8 u |
9x1 = 9 u |
25x1 = 25 u |
Change |
- 7 u |
- 7 u |
|
|
After |
10x1 = 10 u |
1x1 = 1 u |
9x1 = 9 u |
11x1 = 11 u |
When Abi removed an equal number of grey marbles and silver marbles, the difference between the number of grey marbles and silver marbles at first and in the end remains the same.
LCM of 9 and 9 is 9.
Percentage of the marbles left in the box
=
1125 x 100%
= 1125 x 100%
= 44%
Answer: 44%