In a hall,
15 of the students wore cardigans. After 50 students who wore cardigans entered the hall, the percentage of students who wore cardigans increased to 70%. How many students in the hall did not wear cardigans?
|
Wore cardigans |
Did not wear cardigans |
Before |
1x3 = 3 u |
4x3 = 12 u |
Change |
+ 50 |
|
After |
7x4 = 28 u |
3x4 = 12 u |
70% =
70100 =
710The number of students who did not wear cardigans remains unchanged. LCM of 4 and 3 is 12.
Number of students who wore cardigans and left
= 28 u - 3 u
= 25 u
25 u = 50
1 u = 50 ÷ 25 = 2
Number of students who did not wear cardigans
= 12 u
= 12 x 2
= 24
Answer(s): 24