In a canteen,
25 of the boys wore scarves. After 150 boys who wore scarves entered the canteen, the percentage of boys who wore scarves increased to 90%. How many boys in the canteen did not wear scarves?
|
Wore scarves |
Did not wear scarves |
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 scarves remains unchanged. LCM of 3 and 1 is 3.
Number of boys who wore scarves and left
= 27 u - 2 u
= 25 u
25 u = 150
1 u = 150 ÷ 25 = 6
Number of boys who did not wear scarves
= 3 u
= 3 x 6
= 18
Answer(s): 18