240 people went to a museum.
58 were adults. Some children joined halfway and the ratio of the number of adults to the number of children became 10 : 9. How many children joined the museum halfway?
| |
Adults |
Children |
Total |
| Before |
5x2 =
10 u |
3x2 =
6 u |
8x2 =
16 u |
| Change |
|
+ ? |
|
| After |
10 u |
9 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 10 is 10.
Total number of people at first = 16 u
16 u = 240
1 u = 240 ÷ 16 = 15
Number of children who joined halfway
= 9 u - 6 u
= 3 u
= 3 x 15
= 45
Answer(s): 45
