In a hall,
18 of the boys wore caps. After 322 boys who wore caps entered the hall, the percentage of boys who wore caps increased to 70%. How many boys in the hall did not wear caps?
|
Wore caps |
Did not wear caps |
Before |
1x3 = 3 u |
7x3 = 21 u |
Change |
+ 322 |
|
After |
7x7 = 49 u |
3x7 = 21 u |
70% =
70100 =
710The number of boys who did not wear caps remains unchanged. LCM of 7 and 3 is 21.
Number of boys who wore caps and left
= 49 u - 3 u
= 46 u
46 u = 322
1 u = 322 ÷ 46 = 7
Number of boys who did not wear caps
= 21 u
= 21 x 7
= 147
Answer(s): 147