PSLE Ivory had a basket of white beads and blue beads in the ratio 18 : 7. She removed an equal number of white beads and blue beads from the basket. The ratio of the number of white beads and blue beads left in the basket became 5 : 1. What percentage of the beads were left in the basket?
|
White beads |
Blue beads |
Difference |
Total |
Before |
18x4 = 72 u |
7x4 = 28 u |
11x4 = 44 u |
25x4 = 100 u |
Change |
- 17 u |
- 17 u |
|
|
After |
5x11 = 55 u |
1x11 = 11 u |
4x11 = 44 u |
6x11 = 66 u |
When Ivory removed an equal number of white beads and blue beads, the difference between the number of white beads and blue beads at first and in the end remains the same.
LCM of 11 and 4 is 44.
Percentage of the beads left in the basket
=
66100 x 100%
= 3350 x 100%
= 66%
Answer: 66%