In a school field,
710 of the girls wore ties. After 12 girls who wore ties entered the school field, the percentage of girls who wore ties increased to 75%. How many girls in the school field did not wear ties?
|
Wore ties |
Did not wear ties |
Before |
7x1 = 7 u |
3x1 = 3 u |
Change |
+ 12 |
|
After |
3x3 = 9 u |
1x3 = 3 u |
75% =
75100 =
34The number of girls who did not wear ties remains unchanged. LCM of 3 and 1 is 3.
Number of girls who wore ties and left
= 9 u - 7 u
= 2 u
2 u = 12
1 u = 12 ÷ 2 = 6
Number of girls who did not wear ties
= 3 u
= 3 x 6
= 18
Answer(s): 18