420 people went to a museum.
27 were children. Some adults left halfway and the ratio of the number of children to the number of adults became 6 : 13. How many adults left the museum halfway?
| |
Children |
Adults |
Total |
| Before |
2x3 =
6 u |
5x3 =
15 u |
7x3 =
21 u |
| Change |
|
- ? |
|
| After |
6 u |
13 u |
|
Fraction of the people that were adults at first
= 1 -
27 =
57 Number of children remains unchanged. Make the number of children the same. LCM of 2 and 6 is 6.
Total number of people at first = 21 u
21 u = 420
1 u = 420 ÷ 21 = 20
Number of adults who left halfway
= 15 u - 13 u
= 2 u
= 2 x 20
= 40
Answer(s): 40
