In a hall,
710 of the children wore glasses. After 200 children who wore glasses left the hall, the percentage of children who wore glasses decreased to 30%. How many children in the hall did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
7x7 =
49 u |
3x7 =
21 u |
| Change |
- 200 |
|
| After |
3x3 =
9 u |
7x3 =
21 u |
30% =
30100 =
310The number of children who did not wear glasses remains unchanged. LCM of 3 and 7 is 21.
Number of children who wore glasses and left
= 49 u - 9 u
= 40 u
40 u = 200
1 u = 200 ÷ 40 = 5
Number of children who did not wear glasses
= 21 u
= 21 x 5
= 105
Answer(s): 105
