In a hall,
34 of the pupils wore sweaters. After 162 pupils who wore sweaters left the hall, the percentage of pupils who wore sweaters decreased to 30%. How many pupils in the hall did not wear sweaters?
|
Wore sweaters |
Did not wear sweaters |
Before |
3x7 = 21 u |
1x7 = 7 u |
Change |
- 162 |
|
After |
3x1 = 3 u |
7x1 = 7 u |
30% =
30100 =
310The number of pupils who did not wear sweaters remains unchanged. LCM of 1 and 7 is 7.
Number of pupils who wore sweaters and left
= 21 u - 3 u
= 18 u
18 u = 162
1 u = 162 ÷ 18 = 9
Number of pupils who did not wear sweaters
= 7 u
= 7 x 9
= 63
Answer(s): 63