In a school field,
15 of the students wore cardigans. After 135 students who wore cardigans entered the school field, the percentage of students who wore cardigans increased to 80%. How many students in the school field did not wear cardigans?
|
Wore cardigans |
Did not wear cardigans |
Before |
1x1 = 1 u |
4x1 = 4 u |
Change |
+ 135 |
|
After |
4x4 = 16 u |
1x4 = 4 u |
80% =
80100 =
45The number of students who did not wear cardigans remains unchanged. LCM of 4 and 1 is 4.
Number of students who wore cardigans and left
= 16 u - 1 u
= 15 u
15 u = 135
1 u = 135 ÷ 15 = 9
Number of students who did not wear cardigans
= 4 u
= 4 x 9
= 36
Answer(s): 36