In a tuckshop,
910 of the girls wore glasses. After 240 girls who wore glasses left the tuckshop, the percentage of girls who wore glasses decreased to 10%. How many girls in the tuckshop did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
9x9 =
81 u |
1x9 =
9 u |
| Change |
- 240 |
|
| After |
1x1 =
1 u |
9x1 =
9 u |
10% =
10100 =
110The number of girls who did not wear glasses remains unchanged. LCM of 1 and 9 is 9.
Number of girls who wore glasses and left
= 81 u - 1 u
= 80 u
80 u = 240
1 u = 240 ÷ 80 = 3
Number of girls who did not wear glasses
= 9 u
= 9 x 3
= 27
Answer(s): 27
