In a school field,
910 of the boys wore ties. After 140 boys who wore ties left the school field, the percentage of boys who wore ties decreased to 20%. How many boys in the school field did not wear ties?
|
Wore ties |
Did not wear ties |
Before |
9x4 = 36 u |
1x4 = 4 u |
Change |
- 140 |
|
After |
1x1 = 1 u |
4x1 = 4 u |
20% =
20100 =
15The number of boys who did not wear ties remains unchanged. LCM of 1 and 4 is 4.
Number of boys who wore ties and left
= 36 u - 1 u
= 35 u
35 u = 140
1 u = 140 ÷ 35 = 4
Number of boys who did not wear ties
= 4 u
= 4 x 4
= 16
Answer(s): 16