If the seventh term of an A.P. is 1/9 and its ninth term is1/7, find its (63)^rd term.

The 24^th term of an A.P. is twice its 10^th term. Show that its 72^nd term is 4 times its 15^th term.

Find the number of natural numbers between 101 and 999 which are divisible by both 2 and 5.

The sum of 5^th and 9^th terms of an AP is 30. If its 25^th term is three times its 8^th term, find the AP.

Find where 0 (zero) is a term of the A.P.