A survey of 500 farmers showed that of the farmers, 126 grew only wheat, 113 grew only corn, 92 grew only oats, 204 grew wheat, 64 grew wheat and com, 50 grew wheat and oats, and 188 grew corn. Determine the number of farmers who a) grew at least one of the three, b) grew all three, c) did not grow any of the three, and d)
grew exactly two of the three
a) Of the farmers, grew at least one of the three crops
(Simplify your answer.)