In a parade square,
29 of the children wore glasses. After 387 children who wore glasses entered the parade square, the percentage of children who wore glasses increased to 70%. How many children in the parade square did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
2x3 =
6 u |
7x3 =
21 u |
| Change |
+ 387 |
|
| After |
7x7 =
49 u |
3x7 =
21 u |
70% =
70100 =
710The number of children who did not wear glasses remains unchanged. LCM of 7 and 3 is 21.
Number of children who wore glasses and left
= 49 u - 6 u
= 43 u
43 u = 387
1 u = 387 ÷ 43 = 9
Number of children who did not wear glasses
= 21 u
= 21 x 9
= 189
Answer(s): 189
