In a school field,
13 of the students wore cardigans. After 34 students who wore cardigans entered the school field, the percentage of students who wore cardigans increased to 90%. How many students in the school field did not wear cardigans?
| |
Wore cardigans |
Did not wear cardigans |
| Before |
1x1 =
1 u |
2x1 =
2 u |
| Change |
+ 34 |
|
| After |
9x2 =
18 u |
1x2 =
2 u |
90% =
90100 =
910The number of students who did not wear cardigans remains unchanged. LCM of 2 and 1 is 2.
Number of students who wore cardigans and left
= 18 u - 1 u
= 17 u
17 u = 34
1 u = 34 ÷ 17 = 2
Number of students who did not wear cardigans
= 2 u
= 2 x 2
= 4
Answer(s): 4
