In a basketball court,
710 of the boys wore cardigans. After 60 boys who wore cardigans entered the basketball court, the percentage of boys who wore cardigans increased to 90%. How many boys in the basketball court did not wear cardigans?
| |
Wore cardigans |
Did not wear cardigans |
| Before |
7x1 =
7 u |
3x1 =
3 u |
| Change |
+ 60 |
|
| After |
9x3 =
27 u |
1x3 =
3 u |
90% =
90100 =
910The number of boys who did not wear cardigans remains unchanged. LCM of 3 and 1 is 3.
Number of boys who wore cardigans and left
= 27 u - 7 u
= 20 u
20 u = 60
1 u = 60 ÷ 20 = 3
Number of boys who did not wear cardigans
= 3 u
= 3 x 3
= 9
Answer(s): 9
