PSLE Yoko had a bag of purple beads and pink beads in the ratio 13 : 7. She removed an equal number of purple beads and pink beads from the bag. The ratio of the number of purple beads and pink beads left in the bag became 3 : 1. What percentage of the beads were left in the bag?
|
Purple beads |
Pink beads |
Difference |
Total |
Before |
13x1 = 13 u |
7x1 = 7 u |
6x1 = 6 u |
20x1 = 20 u |
Change |
- 4 u |
- 4 u |
|
|
After |
3x3 = 9 u |
1x3 = 3 u |
2x3 = 6 u |
4x3 = 12 u |
When Yoko removed an equal number of purple beads and pink beads, the difference between the number of purple beads and pink beads at first and in the end remains the same.
LCM of 6 and 2 is 6.
Percentage of the beads left in the bag
=
1220 x 100%
= 35 x 100%
= 60%
Answer: 60%