PSLE Olivia had a box of red beads and yellow beads in the ratio 17 : 8. She removed an equal number of red beads and yellow beads from the box. The ratio of the number of red beads and yellow beads left in the box became 7 : 1. What percentage of the beads were left in the box?
|
Red beads |
Yellow beads |
Difference |
Total |
Before |
17x2 = 34 u |
8x2 = 16 u |
9x2 = 18 u |
25x2 = 50 u |
Change |
- 13 u |
- 13 u |
|
|
After |
7x3 = 21 u |
1x3 = 3 u |
6x3 = 18 u |
8x3 = 24 u |
When Olivia removed an equal number of red beads and yellow beads, the difference between the number of red beads and yellow beads at first and in the end remains the same.
LCM of 9 and 6 is 18.
Percentage of the beads left in the box
=
2450 x 100%
= 1225 x 100%
= 48%
Answer: 48%