G. Clark has a job as a car salesman. He is paid a basic salary of £1,200 per month, plus commission of 2 per cent on the value of his car sales. During the month of April 2016 he sells £240,000 worth of cars. The first £800 per month is free of income tax, on the next £120 he pays tax at the 20 per cent rate and above that he pays at the 25 per cent rate. He also pays National Insurance for the month of £620. Calculate his net pay for the month.