Afarmer who has fixed amounts of land and capital finds that total product is 24 for the first worker hired; 32 when two workers are hired; 37 when three are hired; and 40 when four are hired. the farmer's product sells for $3 per unit and the wage rate is $13 per worker. how many workers should the farmer hire?
a) 20.b) 32.c) 37.d) 40.