252 people went to a park.
37 were children. Some adults left halfway and the ratio of the number of children to the number of adults became 9 : 10. How many adults left the park halfway?
| |
Children |
Adults |
Total |
| Before |
3x3 =
9 u |
4x3 =
12 u |
7x3 =
21 u |
| Change |
|
- ? |
|
| After |
9 u |
10 u |
|
Fraction of the people that were adults at first
= 1 -
37 =
47 Number of children remains unchanged. Make the number of children the same. LCM of 3 and 9 is 9.
Total number of people at first = 21 u
21 u = 252
1 u = 252 ÷ 21 = 12
Number of adults who left halfway
= 12 u - 10 u
= 2 u
= 2 x 12
= 24
Answer(s): 24
