408 people went to a bird park.
58 were adults. Some children joined halfway and the ratio of the number of adults to the number of children became 15 : 13. How many children joined the bird park halfway?
| |
Adults |
Children |
Total |
| Before |
5x3 =
15 u |
3x3 =
9 u |
8x3 =
24 u |
| Change |
|
+ ? |
|
| After |
15 u |
13 u |
|
Fraction of the people that were children at first
= 1 -
58 =
38 Number of adults remains unchanged. Make the number of adults the same. LCM of 5 and 15 is 15.
Total number of people at first = 24 u
24 u = 408
1 u = 408 ÷ 24 = 17
Number of children who joined halfway
= 13 u - 9 u
= 4 u
= 4 x 17
= 68
Answer(s): 68
