PSLE Pamela had a basket of pink beads and silver beads in the ratio 18 : 7. She removed an equal number of pink beads and silver beads from the basket. The ratio of the number of pink beads and silver beads left in the basket became 3 : 1. What percentage of the beads were left in the basket?
|
Pink beads |
Silver beads |
Difference |
Total |
Before |
18x2 = 36 u |
7x2 = 14 u |
11x2 = 22 u |
25x2 = 50 u |
Change |
- 3 u |
- 3 u |
|
|
After |
3x11 = 33 u |
1x11 = 11 u |
2x11 = 22 u |
4x11 = 44 u |
When Pamela removed an equal number of pink beads and silver beads, the difference between the number of pink beads and silver beads at first and in the end remains the same.
LCM of 11 and 2 is 22.
Percentage of the beads left in the basket
=
4450 x 100%
= 2225 x 100%
= 88%
Answer: 88%