PSLE Sabrina had a basket of blue marbles and black marbles in the ratio 16 : 9. She removed an equal number of blue marbles and black marbles from the basket. The ratio of the number of blue marbles and black marbles left in the basket became 8 : 1. What percentage of the marbles were left in the basket?
|
Blue marbles |
Black marbles |
Difference |
Total |
Before |
16x1 = 16 u |
9x1 = 9 u |
7x1 = 7 u |
25x1 = 25 u |
Change |
- 8 u |
- 8 u |
|
|
After |
8x1 = 8 u |
1x1 = 1 u |
7x1 = 7 u |
9x1 = 9 u |
When Sabrina removed an equal number of blue marbles and black marbles, the difference between the number of blue marbles and black marbles at first and in the end remains the same.
LCM of 7 and 7 is 7.
Percentage of the marbles left in the basket
=
925 x 100%
= 925 x 100%
= 36%
Answer: 36%