In a school field,
25 of the boys wore caps. After 150 boys who wore caps entered the school field, the percentage of boys who wore caps increased to 90%. How many boys in the school field did not wear caps?
|
Wore caps |
Did not wear caps |
Before |
2x1 = 2 u |
3x1 = 3 u |
Change |
+ 150 |
|
After |
9x3 = 27 u |
1x3 = 3 u |
90% =
90100 =
910The number of boys who did not wear caps remains unchanged. LCM of 3 and 1 is 3.
Number of boys who wore caps and left
= 27 u - 2 u
= 25 u
25 u = 150
1 u = 150 ÷ 25 = 6
Number of boys who did not wear caps
= 3 u
= 3 x 6
= 18
Answer(s): 18