In a hall,
37 of the children wore glasses. After 39 children who wore glasses entered the hall, the percentage of children who wore glasses increased to 80%. How many children in the hall did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
3x1 =
3 u |
4x1 =
4 u |
| Change |
+ 39 |
|
| After |
4x4 =
16 u |
1x4 =
4 u |
80% =
80100 =
45The number of children who did not wear glasses remains unchanged. LCM of 4 and 1 is 4.
Number of children who wore glasses and left
= 16 u - 3 u
= 13 u
13 u = 39
1 u = 39 ÷ 13 = 3
Number of children who did not wear glasses
= 4 u
= 4 x 3
= 12
Answer(s): 12
