In a school field,
19 of the girls wore glasses. After 115 girls who wore glasses entered the school field, the percentage of girls who wore glasses increased to 75%. How many girls in the school field did not wear glasses?
|
Wore glasses |
Did not wear glasses |
Before |
1x1 = 1 u |
8x1 = 8 u |
Change |
+ 115 |
|
After |
3x8 = 24 u |
1x8 = 8 u |
75% =
75100 =
34The number of girls who did not wear glasses remains unchanged. LCM of 8 and 1 is 8.
Number of girls who wore glasses and left
= 24 u - 1 u
= 23 u
23 u = 115
1 u = 115 ÷ 23 = 5
Number of girls who did not wear glasses
= 8 u
= 8 x 5
= 40
Answer(s): 40