PSLE Gem had a bag of brown marbles and green marbles in the ratio 18 : 7. She removed an equal number of brown marbles and green marbles from the bag. The ratio of the number of brown marbles and green marbles left in the bag became 9 : 1. What percentage of the marbles were left in the bag?
|
Brown marbles |
Green marbles |
Difference |
Total |
Before |
18x8 = 144 u |
7x8 = 56 u |
11x8 = 88 u |
25x8 = 200 u |
Change |
- 45 u |
- 45 u |
|
|
After |
9x11 = 99 u |
1x11 = 11 u |
8x11 = 88 u |
10x11 = 110 u |
When Gem removed an equal number of brown marbles and green marbles, the difference between the number of brown marbles and green marbles at first and in the end remains the same.
LCM of 11 and 8 is 88.
Percentage of the marbles left in the bag
=
110200 x 100%
= 1120 x 100%
= 55%
Answer: 55%