In a hall,
38 of the pupils wore sweaters. After 36 pupils who wore sweaters left the hall, the percentage of pupils who wore sweaters decreased to 25%. How many pupils in the hall did not wear sweaters?
|
Wore sweaters |
Did not wear sweaters |
Before |
3x3 = 9 u |
5x3 = 15 u |
Change |
- 36 |
|
After |
1x5 = 5 u |
3x5 = 15 u |
25% =
25100 =
14The number of pupils who did not wear sweaters remains unchanged. LCM of 5 and 3 is 15.
Number of pupils who wore sweaters and left
= 9 u - 5 u
= 4 u
4 u = 36
1 u = 36 ÷ 4 = 9
Number of pupils who did not wear sweaters
= 15 u
= 15 x 9
= 135
Answer(s): 135