In a school field,
67 of the students wore vests. After 156 students who wore vests left the school field, the percentage of students who wore vests decreased to 30%. How many students in the school field did not wear vests?
| |
Wore vests |
Did not wear vests |
| Before |
6x7 =
42 u |
1x7 =
7 u |
| Change |
- 156 |
|
| After |
3x1 =
3 u |
7x1 =
7 u |
30% =
30100 =
310The number of students who did not wear vests remains unchanged. LCM of 1 and 7 is 7.
Number of students who wore vests and left
= 42 u - 3 u
= 39 u
39 u = 156
1 u = 156 ÷ 39 = 4
Number of students who did not wear vests
= 7 u
= 7 x 4
= 28
Answer(s): 28
