PSLE Shannon had a basket of purple beads and white beads in the ratio 17 : 7. She removed an equal number of purple beads and white beads from the basket. The ratio of the number of purple beads and white beads left in the basket became 7 : 2. What percentage of the beads were left in the basket?
|
Purple beads |
White beads |
Difference |
Total |
Before |
17x1 = 17 u |
7x1 = 7 u |
10x1 = 10 u |
24x1 = 24 u |
Change |
- 3 u |
- 3 u |
|
|
After |
7x2 = 14 u |
2x2 = 4 u |
5x2 = 10 u |
9x2 = 18 u |
When Shannon removed an equal number of purple beads and white beads, the difference between the number of purple beads and white beads at first and in the end remains the same.
LCM of 10 and 5 is 10.
Percentage of the beads left in the basket
=
1824 x 100%
= 34 x 100%
= 75%
Answer: 75%