Farmer John (not the bacon guy) raises ducks and cows. He has 54 animals which all together have 122 feet. How many of each type of animals does Farmer John have?

C + D = 54

therefore C = 54-D

4C + 2D = 122

Substitute 54-D for C in the third equation and solve for D. Insert that value into the second equation to solve for C. Check by putting both values into the third equation.

To solve this problem, we can set up a system of equations. Let's say the number of ducks is represented by 'D' and the number of cows is represented by 'C'.

Since each duck has 2 feet and each cow has 4 feet, we can create an equation for the total number of feet:

2D + 4C = 122

Now, we know that the total number of animals is 54, so we can create another equation:

D + C = 54

To solve this system of equations, we can use substitution or elimination. Let's solve it using elimination:

Multiply the second equation by 2 so that the coefficients of 'D' in both equations will cancel each other out:

2D + 4C = 122
2(D + C) = 2(54)
2D + 4C = 108

Now we have two equivalent equations:

2D + 4C = 122
2D + 4C = 108

Subtract the second equation from the first equation:

(2D + 4C) - (2D + 4C) = 122 - 108
0 = 14

This equation yields an inconsistent result, which means there is no solution that satisfies both equations simultaneously. Therefore, there is no answer to this problem that matches the given information.