672 people went to a tourist attraction.
57 were adults. Some children joined halfway and the ratio of the number of adults to the number of children became 20 : 11. How many children joined the tourist attraction halfway?
| |
Adults |
Children |
Total |
| Before |
5x4 =
20 u |
2x4 =
8 u |
7x4 =
28 u |
| Change |
|
+ ? |
|
| After |
20 u |
11 u |
|
Fraction of the people that were children at first
= 1 -
57 =
27 Number of adults remains unchanged. Make the number of adults the same. LCM of 5 and 20 is 20.
Total number of people at first = 28 u
28 u = 672
1 u = 672 ÷ 28 = 24
Number of children who joined halfway
= 11 u - 8 u
= 3 u
= 3 x 24
= 72
Answer(s): 72
