In a tuckshop,
38 of the students wore cardigans. After 170 students who wore cardigans entered the tuckshop, the percentage of students who wore cardigans increased to 80%. How many students in the tuckshop did not wear cardigans?
| |
Wore cardigans |
Did not wear cardigans |
| Before |
3x1 =
3 u |
5x1 =
5 u |
| Change |
+ 170 |
|
| After |
4x5 =
20 u |
1x5 =
5 u |
80% =
80100 =
45The number of students who did not wear cardigans remains unchanged. LCM of 5 and 1 is 5.
Number of students who wore cardigans and left
= 20 u - 3 u
= 17 u
17 u = 170
1 u = 170 ÷ 17 = 10
Number of students who did not wear cardigans
= 5 u
= 5 x 10
= 50
Answer(s): 50
