PSLE Julie had a box of brown beads and pink beads in the ratio 13 : 7. She removed an equal number of brown beads and pink beads from the box. The ratio of the number of brown beads and pink beads left in the box became 5 : 1. What percentage of the beads were left in the box?
|
Brown beads |
Pink beads |
Difference |
Total |
Before |
13x2 = 26 u |
7x2 = 14 u |
6x2 = 12 u |
20x2 = 40 u |
Change |
- 11 u |
- 11 u |
|
|
After |
5x3 = 15 u |
1x3 = 3 u |
4x3 = 12 u |
6x3 = 18 u |
When Julie removed an equal number of brown beads and pink beads, the difference between the number of brown beads and pink beads at first and in the end remains the same.
LCM of 6 and 4 is 12.
Percentage of the beads left in the box
=
1840 x 100%
= 920 x 100%
= 45%
Answer: 45%