In a tuckshop,
15 of the boys wore cardigans. After 77 boys who wore cardigans entered the tuckshop, the percentage of boys who wore cardigans increased to 75%. How many boys in the tuckshop did not wear cardigans?
| |
Wore cardigans |
Did not wear cardigans |
| Before |
1x1 =
1 u |
4x1 =
4 u |
| Change |
+ 77 |
|
| After |
3x4 =
12 u |
1x4 =
4 u |
75% =
75100 =
34The number of boys who did not wear cardigans remains unchanged. LCM of 4 and 1 is 4.
Number of boys who wore cardigans and left
= 12 u - 1 u
= 11 u
11 u = 77
1 u = 77 ÷ 11 = 7
Number of boys who did not wear cardigans
= 4 u
= 4 x 7
= 28
Answer(s): 28
