504 people went to a concert hall.
57 were children. Some adults left halfway and the ratio of the number of children to the number of adults became 15 : 2. How many adults left the concert hall halfway?
| |
Children |
Adults |
Total |
| Before |
5x3 =
15 u |
2x3 =
6 u |
7x3 =
21 u |
| Change |
|
- ? |
|
| After |
15 u |
2 u |
|
Fraction of the people that were adults at first
= 1 -
57 =
27 Number of children remains unchanged. Make the number of children the same. LCM of 5 and 15 is 15.
Total number of people at first = 21 u
21 u = 504
1 u = 504 ÷ 21 = 24
Number of adults who left halfway
= 6 u - 2 u
= 4 u
= 4 x 24
= 96
Answer(s): 96
