At a farm, there were
57 as many cows and ducks. The farmer added another 29 cows but sold away 40 ducks. In the end, there were 3 ducks more than cows. How many cows and ducks were there altogether in the end?
|
Cows |
Ducks |
Before |
5 u |
7 u |
Change |
+ 29 |
- 40 |
After |
5 u + 29 |
7 u - 40 |
If the farmer had another 3 cows in the end, the number of cows and (chickens) would be the same.
7 u - 40 = 5 u + 29 + 3
7 u - 5 u = 32 + 40
2 u = 72
1 u = 72 ÷ 2 = 36
Number of ducks and cows in the end
= 5 u + 29 + 7 u - 40
= 5 u + 7 u + 29 - 40
= 12 u - 11
= 12 x 36 - 11
= 421
Answer(s): 421