PSLE Nicole had a box of purple beads and green beads in the ratio 18 : 7. She removed an equal number of purple beads and green beads from the box. The ratio of the number of purple beads and green beads left in the box became 9 : 1. What percentage of the beads were left in the box?
|
Purple beads |
Green beads |
Difference |
Total |
Before |
18x8 = 144 u |
7x8 = 56 u |
11x8 = 88 u |
25x8 = 200 u |
Change |
- 45 u |
- 45 u |
|
|
After |
9x11 = 99 u |
1x11 = 11 u |
8x11 = 88 u |
10x11 = 110 u |
When Nicole removed an equal number of purple beads and green beads, the difference between the number of purple beads and green beads at first and in the end remains the same.
LCM of 11 and 8 is 88.
Percentage of the beads left in the box
=
110200 x 100%
= 1120 x 100%
= 55%
Answer: 55%