In a basketball court,
38 of the students wore glasses. After 28 students who wore glasses left the basketball court, the percentage of students who wore glasses decreased to 20%. How many students in the basketball court did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
3x4 =
12 u |
5x4 =
20 u |
| Change |
- 28 |
|
| After |
1x5 =
5 u |
4x5 =
20 u |
20% =
20100 =
15The number of students who did not wear glasses remains unchanged. LCM of 5 and 4 is 20.
Number of students who wore glasses and left
= 12 u - 5 u
= 7 u
7 u = 28
1 u = 28 ÷ 7 = 4
Number of students who did not wear glasses
= 20 u
= 20 x 4
= 80
Answer(s): 80
