In a basketball court,
710 of the boys wore scarves. After 240 boys who wore scarves entered the basketball court, the percentage of boys who wore scarves increased to 90%. How many boys in the basketball court did not wear scarves?
| |
Wore scarves |
Did not wear scarves |
| Before |
7x1 =
7 u |
3x1 =
3 u |
| Change |
+ 240 |
|
| After |
9x3 =
27 u |
1x3 =
3 u |
90% =
90100 =
910The number of boys who did not wear scarves remains unchanged. LCM of 3 and 1 is 3.
Number of boys who wore scarves and left
= 27 u - 7 u
= 20 u
20 u = 240
1 u = 240 ÷ 20 = 12
Number of boys who did not wear scarves
= 3 u
= 3 x 12
= 36
Answer(s): 36
