In a school field,
59 of the pupils wore caps. After 310 pupils who wore caps entered the school field, the percentage of pupils who wore caps increased to 90%. How many pupils in the school field did not wear caps?
|
Wore caps |
Did not wear caps |
Before |
5x1 = 5 u |
4x1 = 4 u |
Change |
+ 310 |
|
After |
9x4 = 36 u |
1x4 = 4 u |
90% =
90100 =
910The number of pupils who did not wear caps remains unchanged. LCM of 4 and 1 is 4.
Number of pupils who wore caps and left
= 36 u - 5 u
= 31 u
31 u = 310
1 u = 310 ÷ 31 = 10
Number of pupils who did not wear caps
= 4 u
= 4 x 10
= 40
Answer(s): 40