In a parade square,
710 of the pupils wore ties. After 20 pupils who wore ties left the parade square, the percentage of pupils who wore ties decreased to 60%. How many pupils in the parade square did not wear ties?
|
Wore ties |
Did not wear ties |
Before |
7x2 = 14 u |
3x2 = 6 u |
Change |
- 20 |
|
After |
3x3 = 9 u |
2x3 = 6 u |
60% =
60100 =
35The number of pupils who did not wear ties remains unchanged. LCM of 3 and 2 is 6.
Number of pupils who wore ties and left
= 14 u - 9 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Number of pupils who did not wear ties
= 6 u
= 6 x 4
= 24
Answer(s): 24