In a school field,
37 of the students wore glasses. After 18 students who wore glasses left the school field, the percentage of students who wore glasses decreased to 30%. How many students in the school field did not wear glasses?
|
Wore glasses |
Did not wear glasses |
Before |
3x7 = 21 u |
4x7 = 28 u |
Change |
- 18 |
|
After |
3x4 = 12 u |
7x4 = 28 u |
30% =
30100 =
310The number of students who did not wear glasses remains unchanged. LCM of 4 and 7 is 28.
Number of students who wore glasses and left
= 21 u - 12 u
= 9 u
9 u = 18
1 u = 18 ÷ 9 = 2
Number of students who did not wear glasses
= 28 u
= 28 x 2
= 56
Answer(s): 56