PSLE Anna had a bag of green beads and purple beads in the ratio 13 : 7. She removed an equal number of green beads and purple beads from the bag. The ratio of the number of green beads and purple beads left in the bag became 4 : 1. What percentage of the beads were left in the bag?
|
Green beads |
Purple beads |
Difference |
Total |
Before |
13x1 = 13 u |
7x1 = 7 u |
6x1 = 6 u |
20x1 = 20 u |
Change |
- 5 u |
- 5 u |
|
|
After |
4x2 = 8 u |
1x2 = 2 u |
3x2 = 6 u |
5x2 = 10 u |
When Anna removed an equal number of green beads and purple beads, the difference between the number of green beads and purple beads at first and in the end remains the same.
LCM of 6 and 3 is 6.
Percentage of the beads left in the bag
=
1020 x 100%
= 12 x 100%
= 50%
Answer: 50%