In a canteen,
29 of the children wore vests. After 78 children who wore vests entered the canteen, the percentage of children who wore vests increased to 80%. How many children in the canteen did not wear vests?
| |
Wore vests |
Did not wear vests |
| Before |
2x1 =
2 u |
7x1 =
7 u |
| Change |
+ 78 |
|
| After |
4x7 =
28 u |
1x7 =
7 u |
80% =
80100 =
45The number of children who did not wear vests remains unchanged. LCM of 7 and 1 is 7.
Number of children who wore vests and left
= 28 u - 2 u
= 26 u
26 u = 78
1 u = 78 ÷ 26 = 3
Number of children who did not wear vests
= 7 u
= 7 x 3
= 21
Answer(s): 21
