At a zoo, there were
25 as many adults as children at first. After 40 adults left, there were 121 more children than adults remaining at a zoo. How many adults were at the zoo at first?
|
Adults |
Children |
Before |
2 u |
5 u |
Change |
- 40 |
|
After |
2 u - 40 |
5 u |
In the end, the number of children was 121 more than the number of adults. If another 121 adults entered the zoo, the number of children and adults would be the same.
5 u = 2 u - 40 + 121
5 u - 2 u = 121 - 40
3 u = 81
1 u = 81 ÷ 3 = 27
Number of adults at first
= 2 u
= 2 x 27
= 54
Answer: 54