560 people went to a stadium.
35 were children. Some adults left halfway and the ratio of the number of children to the number of adults became 12 : 5. How many adults left the stadium halfway?
|
Children |
Adults |
Total |
Before |
3x4 = 12 u |
2x4 = 8 u |
5x4 = 20 u |
Change |
|
- ? |
|
After |
12 u |
5 u |
|
Fraction of the people that were adults at first
= 1 -
35 =
25 Number of children remains unchanged. Make the number of children the same. LCM of 3 and 12 is 12.
Total number of people at first = 20 u
20 u = 560
1 u = 560 ÷ 20 = 28
Number of adults who left halfway
= 8 u - 5 u
= 3 u
= 3 x 28
= 84
Answer(s): 84