In a hall,
25 of the girls wore spectacles. After 100 girls who wore spectacles entered the hall, the percentage of girls who wore spectacles increased to 80%. How many girls in the hall did not wear spectacles?
| |
Wore spectacles |
Did not wear spectacles |
| Before |
2x1 =
2 u |
3x1 =
3 u |
| Change |
+ 100 |
|
| After |
4x3 =
12 u |
1x3 =
3 u |
80% =
80100 =
45The number of girls who did not wear spectacles remains unchanged. LCM of 3 and 1 is 3.
Number of girls who wore spectacles and left
= 12 u - 2 u
= 10 u
10 u = 100
1 u = 100 ÷ 10 = 10
Number of girls who did not wear spectacles
= 3 u
= 3 x 10
= 30
Answer(s): 30
