408 people went to a park.
38 were adults. Some children joined halfway and the ratio of the number of adults to the number of children became 9 : 17. How many children joined the park halfway?
| |
Adults |
Children |
Total |
| Before |
3x3 =
9 u |
5x3 =
15 u |
8x3 =
24 u |
| Change |
|
+ ? |
|
| After |
9 u |
17 u |
|
Fraction of the people that were children at first
= 1 -
38 =
58 Number of adults remains unchanged. Make the number of adults the same. LCM of 3 and 9 is 9.
Total number of people at first = 24 u
24 u = 408
1 u = 408 ÷ 24 = 17
Number of children who joined halfway
= 17 u - 15 u
= 2 u
= 2 x 17
= 34
Answer(s): 34
