In a parade square,
49 of the children wore spectacles. After 128 children who wore spectacles entered the parade square, the percentage of children who wore spectacles increased to 80%. How many children in the parade square did not wear spectacles?
| |
Wore spectacles |
Did not wear spectacles |
| Before |
4x1 =
4 u |
5x1 =
5 u |
| Change |
+ 128 |
|
| After |
4x5 =
20 u |
1x5 =
5 u |
80% =
80100 =
45The number of children who did not wear spectacles remains unchanged. LCM of 5 and 1 is 5.
Number of children who wore spectacles and left
= 20 u - 4 u
= 16 u
16 u = 128
1 u = 128 ÷ 16 = 8
Number of children who did not wear spectacles
= 5 u
= 5 x 8
= 40
Answer(s): 40
