In a tuckshop,
37 of the boys wore vests. After 21 boys who wore vests entered the tuckshop, the percentage of boys who wore vests increased to 60%. How many boys in the tuckshop did not wear vests?
| |
Wore vests |
Did not wear vests |
| Before |
3x1 =
3 u |
4x1 =
4 u |
| Change |
+ 21 |
|
| After |
3x2 =
6 u |
2x2 =
4 u |
60% =
60100 =
35The number of boys who did not wear vests remains unchanged. LCM of 4 and 2 is 4.
Number of boys who wore vests and left
= 6 u - 3 u
= 3 u
3 u = 21
1 u = 21 ÷ 3 = 7
Number of boys who did not wear vests
= 4 u
= 4 x 7
= 28
Answer(s): 28
