Assume exactly the same circumstances as in Activity 7.4, except that the garage is busy at the moment. If a mechanic undertakes the engine-replacement job, it will mean that other work the mechanic could have done during the seven hours, and which could have been charged to a customer, will not be undertaken. The garage’s labour charge is £60 an hour, although the mechanic is only paid £15 an hour.

What is the minimum price at which the garage should sell the car, with a reconditioned engine fitted, under these altered circumstances?