Please make it clear and fast.

Problem 2: A company is considering the purchase of a generating set to supply the electrical needs of his office during brownouts. The generating set costs P 70,000 with a life of 10 years with a salvage value of P 10,000. The daily operating cost is P 50 per hour. During a brownout, the office operation will be delayed which cause a loss of P 150 per hour. At 18% interest rate, how frequent( in number of hours per year ) is the brownout to justify the purchase of the generator set