Question

A good costs a basic £180 a unit but if an order is made for more than 10 units this

price is reduced by a discount of £2 for every one unit increase in the size of an

order (up to a maximum of 60 units purchased), i.e. if the order size is 11, price

is £178; if it is 12, price is £176 etc. Write an expression for the total cost of an

order in terms of order size and simplify it. Assume order size is between 10 and

60 units

Answer 1

$$q(180-2(q-10))=180q-2q^2+20q=200q-2q^2$$