In a parade square,
710 of the girls wore scarves. After 200 girls who wore scarves left the parade square, the percentage of girls who wore scarves decreased to 30%. How many girls in the parade square did not wear scarves?
| |
Wore scarves |
Did not wear scarves |
| Before |
7x7 =
49 u |
3x7 =
21 u |
| Change |
- 200 |
|
| After |
3x3 =
9 u |
7x3 =
21 u |
30% =
30100 =
310The number of girls who did not wear scarves remains unchanged. LCM of 3 and 7 is 21.
Number of girls who wore scarves and left
= 49 u - 9 u
= 40 u
40 u = 200
1 u = 200 ÷ 40 = 5
Number of girls who did not wear scarves
= 21 u
= 21 x 5
= 105
Answer(s): 105
