PSLE Jane had a bag of gold marbles and red marbles in the ratio 17 : 8. She removed an equal number of gold marbles and red marbles from the bag. The ratio of the number of gold marbles and red marbles left in the bag became 5 : 1. What percentage of the marbles were left in the bag?
|
Gold marbles |
Red marbles |
Difference |
Total |
Before |
17x4 = 68 u |
8x4 = 32 u |
9x4 = 36 u |
25x4 = 100 u |
Change |
- 23 u |
- 23 u |
|
|
After |
5x9 = 45 u |
1x9 = 9 u |
4x9 = 36 u |
6x9 = 54 u |
When Jane removed an equal number of gold marbles and red marbles, the difference between the number of gold marbles and red marbles at first and in the end remains the same.
LCM of 9 and 4 is 36.
Percentage of the marbles left in the bag
=
54100 x 100%
= 2750 x 100%
= 54%
Answer: 54%