A partner has withdrawn the following sums of money during the half year ended June 30,1994: $ 10th January 2,000 18th February 1,200 5th March 600 12th April 800 21st May 1,000 1st June 600 Find out the Average Due date and Calculate the interest to be charged at the rate of 10 per cent for half year ended June 30, 1994.