In a school field,
110 of the students wore caps. After 720 students who wore caps entered the school field, the percentage of students who wore caps increased to 90%. How many students in the school field did not wear caps?
|
Wore caps |
Did not wear caps |
Before |
1x1 = 1 u |
9x1 = 9 u |
Change |
+ 720 |
|
After |
9x9 = 81 u |
1x9 = 9 u |
90% =
90100 =
910The number of students who did not wear caps remains unchanged. LCM of 9 and 1 is 9.
Number of students who wore caps and left
= 81 u - 1 u
= 80 u
80 u = 720
1 u = 720 ÷ 80 = 9
Number of students who did not wear caps
= 9 u
= 9 x 9
= 81
Answer(s): 81