In a tuckshop,
89 of the pupils wore glasses. After 158 pupils who wore glasses left the tuckshop, the percentage of pupils who wore glasses decreased to 45%. How many pupils in the tuckshop did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
8x11 =
88 u |
1x11 =
11 u |
| Change |
- 158 |
|
| After |
9x1 =
9 u |
11x1 =
11 u |
45% =
45100 =
920The number of pupils who did not wear glasses remains unchanged. LCM of 1 and 11 is 11.
Number of pupils who wore glasses and left
= 88 u - 9 u
= 79 u
79 u = 158
1 u = 158 ÷ 79 = 2
Number of pupils who did not wear glasses
= 11 u
= 11 x 2
= 22
Answer(s): 22
