In a canteen,
58 of the boys wore ties. After 28 boys who wore ties entered the canteen, the percentage of boys who wore ties increased to 80%. How many boys in the canteen did not wear ties?
|
Wore ties |
Did not wear ties |
Before |
5x1 = 5 u |
3x1 = 3 u |
Change |
+ 28 |
|
After |
4x3 = 12 u |
1x3 = 3 u |
80% =
80100 =
45The number of boys who did not wear ties remains unchanged. LCM of 3 and 1 is 3.
Number of boys who wore ties and left
= 12 u - 5 u
= 7 u
7 u = 28
1 u = 28 ÷ 7 = 4
Number of boys who did not wear ties
= 3 u
= 3 x 4
= 12
Answer(s): 12