In a hall,
17 of the students wore cardigans. After 39 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 |
1x1 = 1 u |
6x1 = 6 u |
Change |
+ 39 |
|
After |
7x2 = 14 u |
3x2 = 6 u |
70% =
70100 =
710The number of students who did not wear cardigans remains unchanged. LCM of 6 and 3 is 6.
Number of students who wore cardigans and left
= 14 u - 1 u
= 13 u
13 u = 39
1 u = 39 ÷ 13 = 3
Number of students who did not wear cardigans
= 6 u
= 6 x 3
= 18
Answer(s): 18