In a parade square,
19 of the children wore spectacles. After 142 children who wore spectacles entered the parade square, the percentage of children who wore spectacles increased to 90%. How many children in the parade square did not wear spectacles?
|
Wore spectacles |
Did not wear spectacles |
Before |
1x1 = 1 u |
8x1 = 8 u |
Change |
+ 142 |
|
After |
9x8 = 72 u |
1x8 = 8 u |
90% =
90100 =
910The number of children who did not wear spectacles remains unchanged. LCM of 8 and 1 is 8.
Number of children who wore spectacles and left
= 72 u - 1 u
= 71 u
71 u = 142
1 u = 142 ÷ 71 = 2
Number of children who did not wear spectacles
= 8 u
= 8 x 2
= 16
Answer(s): 16