In a school field,
47 of the boys wore cardigans. After 207 boys who wore cardigans entered the school field, the percentage of boys who wore cardigans increased to 90%. How many boys in the school field did not wear cardigans?
|
Wore cardigans |
Did not wear cardigans |
Before |
4x1 = 4 u |
3x1 = 3 u |
Change |
+ 207 |
|
After |
9x3 = 27 u |
1x3 = 3 u |
90% =
90100 =
910The number of boys who did not wear cardigans remains unchanged. LCM of 3 and 1 is 3.
Number of boys who wore cardigans and left
= 27 u - 4 u
= 23 u
23 u = 207
1 u = 207 ÷ 23 = 9
Number of boys who did not wear cardigans
= 3 u
= 3 x 9
= 27
Answer(s): 27