320 people went to a museum.
34 were adults. Some children left halfway and the ratio of the number of adults to the number of children became 12 : 1. How many children left the museum halfway?
| |
Adults |
Children |
Total |
| Before |
3x4 =
12 u |
1x4 =
4 u |
4x4 =
16 u |
| Change |
|
- ? |
|
| After |
12 u |
1 u |
|
Fraction of the people that were children at first
= 1 -
34 =
14 Number of adults remains unchanged. Make the number of adults the same. LCM of 3 and 12 is 12.
Total number of people at first = 16 u
16 u = 320
1 u = 320 ÷ 16 = 20
Number of children who left halfway
= 4 u - 1 u
= 3 u
= 3 x 20
= 60
Answer(s): 60
