Question 1094481
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Let the number of cows be x.

Then the number of chickens is (x+40),

     the number of pigs is (x-10),

     the number of sheep is ((x+40) - 20) = (x+20),

The number of horses is 4.



Altogether

    cows + chicken + pigs + sheep + horses = 110  ====>


     x   +  (x+40) + (x-10) + (x+20) + 4 = 110  ====>


    4x + 40 - 10 +20 + 4 = 110  ====>

    4x + 54 = 110  ====>  4x = 110-54 = 56  ====>  x = {{{56/4}}} = 14.


So, farmer Del has 14 cows.


From this point, can you complete the solution on your own ?
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