PSLE Esther had a box of purple beads and blue beads in the ratio 13 : 7. She removed an equal number of purple beads and blue beads from the box. The ratio of the number of purple beads and blue beads left in the box became 6 : 1. What percentage of the beads were left in the box?
|
Purple beads |
Blue beads |
Difference |
Total |
Before |
13x5 = 65 u |
7x5 = 35 u |
6x5 = 30 u |
20x5 = 100 u |
Change |
- 29 u |
- 29 u |
|
|
After |
6x6 = 36 u |
1x6 = 6 u |
5x6 = 30 u |
7x6 = 42 u |
When Esther removed an equal number of purple beads and blue beads, the difference between the number of purple beads and blue beads at first and in the end remains the same.
LCM of 6 and 5 is 30.
Percentage of the beads left in the box
=
42100 x 100%
= 2150 x 100%
= 42%
Answer: 42%