In a hall,
58 of the children wore vests. After 51 children who wore vests left the hall, the percentage of children who wore vests decreased to 20%. How many children in the hall did not wear vests?
| |
Wore vests |
Did not wear vests |
| Before |
5x4 =
20 u |
3x4 =
12 u |
| Change |
- 51 |
|
| After |
1x3 =
3 u |
4x3 =
12 u |
20% =
20100 =
15The number of children who did not wear vests remains unchanged. LCM of 3 and 4 is 12.
Number of children who wore vests and left
= 20 u - 3 u
= 17 u
17 u = 51
1 u = 51 ÷ 17 = 3
Number of children who did not wear vests
= 12 u
= 12 x 3
= 36
Answer(s): 36
