Find the 20^th and nth terms of the G.P.

31

A man starts repaying a loan as first instalment of Rs. 100. If he increases the instalment by Rs.5 every month, what amount will he pay in the 30^th instalment.

32

The difference between any two consecutive interior angles of a polygon is 5⁰. If the smallest angle is 120⁰, find the number of the sides of the polygon.

34

Find the 12^th term of a G.P. whose 8^th term is 192 and the common ratio is 2.

35

The 5^th, 8^th and 11^th terms of a G.P. are p, q and s, respectively. Show that q² = ps.