For the A.P.: -3,-7,-11,..., can we find a30−a20 without actually finding a30 and a20? Give reasons for your answer.
IF an denotes the nth term of the AP 2, 7, 12, 17, ..., find the value of (a30−a20).
Find a30−a20 for the A.P. (i) -9,-14,-19,-24,... (ii)a,a+d,a+2d,a+3d,...
In a certian A.P. the 24th term is twice the 10th term. Prove that the 72nd term is twice the 34th term.
The eight term of an A.P. is half of its second term and the eleventh term exceeds one third of its fourth term by 1. Find the 15th term.
If the 5th term of an A.P. is 31 and 25th term is 140 more than the 5th term, find the A.P.
The first term of an A.P. is 5, the common difference is 3 and the last term is 80; find the number of terms.
The sum of 5th and 9th terms of an A.P. is 30. If its 25th term is three times its 8th term, find the A.P.
How many three digit numbers are divisible by 7?