Find the geometric series whose 5th and 8th terms are 80 and 640 respectively.

Find the 10 th term of the sequence whose 7 th and 12 th terms are 34 and 64 respectively.

Find the nth term of an A.P. whose 6th and 8th terms are 12 and 22 respectively :

(a) The 3rd and 19th terms of an A.P. are 13 and 77 respectively. Find the A.P. (b) The 5th and 8th terms of an A.P. are 56 and 95 respectively. Find the 25th term of this A.P. (c) The pth and qth terms of an A.P. are q and p respectively. Prove that its (p + q)th term will be zero.

(a) The 3rd and 19th terms of an A.P. are 13 and 77 respectively. Find the A.P. (b) The 5th and 8th terms of an A.P. are 56 and 95 respectively. Find the 25th term of this A.P. (c) The pth and qth terms of an A.P. are q and p respectively. Prove that its (p + q)th term will be zero.

Find the sum of first 17 terms of an AP whose 4th and 9th terms are -15 and -30 , respectively.

Find the sum of first 17 terms of an AP whose 4th and 9th terms are -15 and -30 , respectively.

(i) The 3rd and 19th terms of an A.P. are 13 and 17 respectively. Find its 10th term. (ii) The 5th and 8th terms of an A.P. are 56 and 95 respectively. Find its 25th term.

(i) The 3rd and 19th terms of an A.P. are 13 and 17 respectively. Find its 10th term. (ii) The 5th and 8th terms of an A.P. are 56 and 95 respectively. Find its 25th term.

The first term of an A.P. whose 8th and 12th term are 39, 59 respectively.