In a canteen,
29 of the pupils wore scarves. After 427 pupils who wore scarves entered the canteen, the percentage of pupils who wore scarves increased to 90%. How many pupils in the canteen did not wear scarves?
|
Wore scarves |
Did not wear scarves |
Before |
2x1 = 2 u |
7x1 = 7 u |
Change |
+ 427 |
|
After |
9x7 = 63 u |
1x7 = 7 u |
90% =
90100 =
910The number of pupils who did not wear scarves remains unchanged. LCM of 7 and 1 is 7.
Number of pupils who wore scarves and left
= 63 u - 2 u
= 61 u
61 u = 427
1 u = 427 ÷ 61 = 7
Number of pupils who did not wear scarves
= 7 u
= 7 x 7
= 49
Answer(s): 49