In a hall,
78 of the students wore ties. After 160 students who wore ties left the hall, the percentage of students who wore ties decreased to 25%. How many students in the hall did not wear ties?
| |
Wore ties |
Did not wear ties |
| Before |
7x3 =
21 u |
1x3 =
3 u |
| Change |
- 160 |
|
| After |
1x1 =
1 u |
3x1 =
3 u |
25% =
25100 =
14The number of students who did not wear ties remains unchanged. LCM of 1 and 3 is 3.
Number of students who wore ties and left
= 21 u - 1 u
= 20 u
20 u = 160
1 u = 160 ÷ 20 = 8
Number of students who did not wear ties
= 3 u
= 3 x 8
= 24
Answer(s): 24
