PSLE Victoria had a basket of brown beads and black beads in the ratio 13 : 7. She removed an equal number of brown beads and black beads from the basket. The ratio of the number of brown beads and black beads left in the basket became 4 : 1. What percentage of the beads were left in the basket?
|
Brown beads |
Black beads |
Difference |
Total |
Before |
13x1 = 13 u |
7x1 = 7 u |
6x1 = 6 u |
20x1 = 20 u |
Change |
- 5 u |
- 5 u |
|
|
After |
4x2 = 8 u |
1x2 = 2 u |
3x2 = 6 u |
5x2 = 10 u |
When Victoria removed an equal number of brown beads and black beads, the difference between the number of brown beads and black beads at first and in the end remains the same.
LCM of 6 and 3 is 6.
Percentage of the beads left in the basket
=
1020 x 100%
= 12 x 100%
= 50%
Answer: 50%