A merchant paid $300 for a shipment of x identical calculators.
The merchant used 2 of the calculators as demonstrators and sold
each of the others for $5 more than the average (arithmetic mean)
cost of the x calculators. If the total revenue from the sale of
the calculators was $120 more than the cost of the shipment, how many
calculators were in the shipment?
(300/x+5)(x-2) = 120+300
Instead of solving the equation substitute the answers for x.
Try the easy one e) 30. ((300/30)+5)(30-2)=420