In a parade square,
29 of the boys wore caps. After 171 boys who wore caps entered the parade square, the percentage of boys who wore caps increased to 75%. How many boys in the parade square did not wear caps?
|
Wore caps |
Did not wear caps |
Before |
2x1 = 2 u |
7x1 = 7 u |
Change |
+ 171 |
|
After |
3x7 = 21 u |
1x7 = 7 u |
75% =
75100 =
34The number of boys who did not wear caps remains unchanged. LCM of 7 and 1 is 7.
Number of boys who wore caps and left
= 21 u - 2 u
= 19 u
19 u = 171
1 u = 171 ÷ 19 = 9
Number of boys who did not wear caps
= 7 u
= 7 x 9
= 63
Answer(s): 63