608 people went to a zoo.
38 were adults. Some children joined halfway and the ratio of the number of adults to the number of children became 12 : 23. How many children joined the zoo halfway?
| |
Adults |
Children |
Total |
| Before |
3x4 =
12 u |
5x4 =
20 u |
8x4 =
32 u |
| Change |
|
+ ? |
|
| After |
12 u |
23 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 12 is 12.
Total number of people at first = 32 u
32 u = 608
1 u = 608 ÷ 32 = 19
Number of children who joined halfway
= 23 u - 20 u
= 3 u
= 3 x 19
= 57
Answer(s): 57
