Solve the following. Show your complete solution. Use 3 methods of Economic Studies. A man formerly employed as a chief mechanic of an automobile repair shop has saved P1,000,000 which are now...

Solve the following. Show your complete solution. Use 3 methods of Economic Studies.

A man formerly employed as a chief mechanic of an automobile repair shop has saved P1,000,000 which are now invested in certain securities giving him an annual dividend of 15%. He now plans to invest this amount in his own repair shop. In his present job, he is earning P25,000 per month, but he has to resign to run his own business. He will need the services of the following: 2 mechanics each earning P400 a day, and 8 helpers earning P200 a day. These men will work on average 300 days a year. His other expenses are the following:

Rental = P30,000 a month

Miscellaneous = P25,000 a month

Sales tax = 3% of gross income

Insurance = 2%

The length of his lease is 5 years. If the average charge for each car repair by his shop is P1,000. Determine the number of cars he must service in one year so that he will obtain a profit of at least 20% on his investment?