1. There are two branches of an establishment employing 200 and 160 persons respectively.

If the AMs of the monthly salaries paid by the two branches are rs. 550 and rs. 450

respectivvely, find AM of the salaries of the employees of the establishment as a whole.

2. Calculate the median for the following frequency distribution

Marks 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

No of

students

7 15 24 31 42 30 26 15 10

6. For the cost function y = 500x - 40x2 + 3x3 for x units, find the average cost, marginal

cost and marginal average cost.

3. A man borrows rs. 1500 and agrees to repay the debt in 5 equal instalmenst with 6%

interest, compounded annually. If the first payment is to be made at the end of the first

year, how much should each payment be?