PSLE Tammy had a bag of silver beads and brown beads in the ratio 16 : 9. She removed an equal number of silver beads and brown beads from the bag. The ratio of the number of silver beads and brown beads left in the bag became 3 : 1. What percentage of the beads were left in the bag?
|
Silver beads |
Brown beads |
Difference |
Total |
Before |
16x2 = 32 u |
9x2 = 18 u |
7x2 = 14 u |
25x2 = 50 u |
Change |
- 11 u |
- 11 u |
|
|
After |
3x7 = 21 u |
1x7 = 7 u |
2x7 = 14 u |
4x7 = 28 u |
When Tammy removed an equal number of silver beads and brown beads, the difference between the number of silver beads and brown beads at first and in the end remains the same.
LCM of 7 and 2 is 14.
Percentage of the beads left in the bag
=
2850 x 100%
= 1425 x 100%
= 56%
Answer: 56%