PSLE Sabrina had a basket of gold marbles and silver marbles in the ratio 18 : 7. She removed an equal number of gold marbles and silver marbles from the basket. The ratio of the number of gold marbles and silver marbles left in the basket became 3 : 1. What percentage of the marbles were left in the basket?
|
Gold marbles |
Silver marbles |
Difference |
Total |
Before |
18x2 = 36 u |
7x2 = 14 u |
11x2 = 22 u |
25x2 = 50 u |
Change |
- 3 u |
- 3 u |
|
|
After |
3x11 = 33 u |
1x11 = 11 u |
2x11 = 22 u |
4x11 = 44 u |
When Sabrina removed an equal number of gold marbles and silver marbles, the difference between the number of gold marbles and silver marbles at first and in the end remains the same.
LCM of 11 and 2 is 22.
Percentage of the marbles left in the basket
=
4450 x 100%
= 2225 x 100%
= 88%
Answer: 88%