In a parade square,
59 of the girls wore vests. After 55 girls who wore vests entered the parade square, the percentage of girls who wore vests increased to 80%. How many girls in the parade square did not wear vests?
| |
Wore vests |
Did not wear vests |
| Before |
5x1 =
5 u |
4x1 =
4 u |
| Change |
+ 55 |
|
| After |
4x4 =
16 u |
1x4 =
4 u |
80% =
80100 =
45The number of girls who did not wear vests remains unchanged. LCM of 4 and 1 is 4.
Number of girls who wore vests and left
= 16 u - 5 u
= 11 u
11 u = 55
1 u = 55 ÷ 11 = 5
Number of girls who did not wear vests
= 4 u
= 4 x 5
= 20
Answer(s): 20
