In a hall,
38 of the pupils wore scarves. After 144 pupils who wore scarves entered the hall, the percentage of pupils who wore scarves increased to 75%. How many pupils in the hall did not wear scarves?
| |
Wore scarves |
Did not wear scarves |
| Before |
3x1 =
3 u |
5x1 =
5 u |
| Change |
+ 144 |
|
| After |
3x5 =
15 u |
1x5 =
5 u |
75% =
75100 =
34The number of pupils who did not wear scarves remains unchanged. LCM of 5 and 1 is 5.
Number of pupils who wore scarves and left
= 15 u - 3 u
= 12 u
12 u = 144
1 u = 144 ÷ 12 = 12
Number of pupils who did not wear scarves
= 5 u
= 5 x 12
= 60
Answer(s): 60
