In a canteen,
27 of the pupils wore vests. After 36 pupils who wore vests left the canteen, the percentage of pupils who wore vests decreased to 20%. How many pupils in the canteen did not wear vests?
|
Wore vests |
Did not wear vests |
Before |
2x4 = 8 u |
5x4 = 20 u |
Change |
- 36 |
|
After |
1x5 = 5 u |
4x5 = 20 u |
20% =
20100 =
15The number of pupils who did not wear vests remains unchanged. LCM of 5 and 4 is 20.
Number of pupils who wore vests and left
= 8 u - 5 u
= 3 u
3 u = 36
1 u = 36 ÷ 3 = 12
Number of pupils who did not wear vests
= 20 u
= 20 x 12
= 240
Answer(s): 240