In a school field,
38 of the boys wore sweaters. After 14 boys who wore sweaters left the school field, the percentage of boys who wore sweaters decreased to 20%. How many boys in the school field did not wear sweaters?
|
Wore sweaters |
Did not wear sweaters |
Before |
3x4 = 12 u |
5x4 = 20 u |
Change |
- 14 |
|
After |
1x5 = 5 u |
4x5 = 20 u |
20% =
20100 =
15The number of boys who did not wear sweaters remains unchanged. LCM of 5 and 4 is 20.
Number of boys who wore sweaters and left
= 12 u - 5 u
= 7 u
7 u = 14
1 u = 14 ÷ 7 = 2
Number of boys who did not wear sweaters
= 20 u
= 20 x 2
= 40
Answer(s): 40