In a hall,
58 of the girls wore spectacles. After 28 girls who wore spectacles entered the hall, the percentage of girls who wore spectacles increased to 75%. How many girls in the hall did not wear spectacles?
|
Wore spectacles |
Did not wear spectacles |
Before |
5x1 = 5 u |
3x1 = 3 u |
Change |
+ 28 |
|
After |
3x3 = 9 u |
1x3 = 3 u |
75% =
75100 =
34The 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
= 9 u - 5 u
= 4 u
4 u = 28
1 u = 28 ÷ 4 = 7
Number of girls who did not wear spectacles
= 3 u
= 3 x 7
= 21
Answer(s): 21