In a school field,
79 of the students wore glasses. After 143 students who wore glasses left the school field, the percentage of students who wore glasses decreased to 20%. How many students in the school field did not wear glasses?
|
Wore glasses |
Did not wear glasses |
Before |
7x2 = 14 u |
2x2 = 4 u |
Change |
- 143 |
|
After |
1x1 = 1 u |
4x1 = 4 u |
20% =
20100 =
15The number of students who did not wear glasses remains unchanged. LCM of 2 and 4 is 4.
Number of students who wore glasses and left
= 14 u - 1 u
= 13 u
13 u = 143
1 u = 143 ÷ 13 = 11
Number of students who did not wear glasses
= 4 u
= 4 x 11
= 44
Answer(s): 44