In a canteen,
47 of the girls wore ties. After 156 girls who wore ties left the canteen, the percentage of girls who wore ties decreased to 20%. How many girls in the canteen did not wear ties?
| |
Wore ties |
Did not wear ties |
| Before |
4x4 =
16 u |
3x4 =
12 u |
| Change |
- 156 |
|
| After |
1x3 =
3 u |
4x3 =
12 u |
20% =
20100 =
15The number of girls who did not wear ties remains unchanged. LCM of 3 and 4 is 12.
Number of girls who wore ties and left
= 16 u - 3 u
= 13 u
13 u = 156
1 u = 156 ÷ 13 = 12
Number of girls who did not wear ties
= 12 u
= 12 x 12
= 144
Answer(s): 144
