In a basketball court,
15 of the students wore vests. After 420 students who wore vests entered the basketball court, the percentage of students who wore vests increased to 90%. How many students in the basketball court did not wear vests?
| |
Wore vests |
Did not wear vests |
| Before |
1x1 =
1 u |
4x1 =
4 u |
| Change |
+ 420 |
|
| After |
9x4 =
36 u |
1x4 =
4 u |
90% =
90100 =
910The number of students who did not wear vests remains unchanged. LCM of 4 and 1 is 4.
Number of students who wore vests and left
= 36 u - 1 u
= 35 u
35 u = 420
1 u = 420 ÷ 35 = 12
Number of students who did not wear vests
= 4 u
= 4 x 12
= 48
Answer(s): 48
