In a parade square,
25 of the pupils wore sweaters. After 110 pupils who wore sweaters entered the parade square, the percentage of pupils who wore sweaters increased to 80%. How many pupils in the parade square did not wear sweaters?
|
Wore sweaters |
Did not wear sweaters |
Before |
2x1 = 2 u |
3x1 = 3 u |
Change |
+ 110 |
|
After |
4x3 = 12 u |
1x3 = 3 u |
80% =
80100 =
45The number of pupils who did not wear sweaters remains unchanged. LCM of 3 and 1 is 3.
Number of pupils who wore sweaters and left
= 12 u - 2 u
= 10 u
10 u = 110
1 u = 110 ÷ 10 = 11
Number of pupils who did not wear sweaters
= 3 u
= 3 x 11
= 33
Answer(s): 33