416 people went to a museum.
58 were children. Some adults joined halfway and the ratio of the number of children to the number of adults became 10 : 9. How many adults joined the museum halfway?
| |
Children |
Adults |
Total |
| Before |
5x2 =
10 u |
3x2 =
6 u |
8x2 =
16 u |
| Change |
|
+ ? |
|
| After |
10 u |
9 u |
|
Fraction of the people that were adults at first
= 1 -
58 =
38 Number of children remains unchanged. Make the number of children the same. LCM of 5 and 10 is 10.
Total number of people at first = 16 u
16 u = 416
1 u = 416 ÷ 16 = 26
Number of adults who joined halfway
= 9 u - 6 u
= 3 u
= 3 x 26
= 78
Answer(s): 78
