In a tuckshop,
710 of the boys wore spectacles. After 160 boys who wore spectacles left the tuckshop, the percentage of boys who wore spectacles decreased to 10%. How many boys in the tuckshop did not wear spectacles?
|
Wore spectacles |
Did not wear spectacles |
Before |
7x3 = 21 u |
3x3 = 9 u |
Change |
- 160 |
|
After |
1x1 = 1 u |
9x1 = 9 u |
10% =
10100 =
110The number of boys who did not wear spectacles remains unchanged. LCM of 3 and 9 is 9.
Number of boys who wore spectacles and left
= 21 u - 1 u
= 20 u
20 u = 160
1 u = 160 ÷ 20 = 8
Number of boys who did not wear spectacles
= 9 u
= 9 x 8
= 72
Answer(s): 72