PSLE Shannon had a bag of grey marbles and purple marbles in the ratio 16 : 9. She removed an equal number of grey marbles and purple marbles from the bag. The ratio of the number of grey marbles and purple marbles left in the bag became 10 : 3. What percentage of the marbles were left in the bag?
|
Grey marbles |
Purple 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 Shannon removed an equal number of grey marbles and purple marbles, the difference between the number of grey marbles and purple marbles at first and in the end remains the same.
LCM of 7 and 7 is 7.
Percentage of the marbles left in the bag
=
1325 x 100%
= 1325 x 100%
= 52%
Answer: 52%