Sum of the first 4 terms of an arithmetic sequence is 72. Sum of the first 9 terms is also 72.
Find the sum of the first five terms?

If the sum of first 8 terms of an Arithmetic progression is 136 and that of first 15 terms is 465, then find the sum of first 25 terms. OR Ths sum of the 5th and 9th terms of an A.P. is 40 and the sum of the 8th and 14th term is 64. Find the sum of the first 20 terms.

If the first four terms of an arithmetic sequence are a,2a,b and (a-6-b) for some numbers a and b, find the sum of the first 100 terms of the sequence.

The sum of first 'n' terms of an arithmetic progression is 210 and sum of its first (n-1) terms is 171. If the first term 3, then write the arithmetic progression.

The sum of first n terms of an arithmetic progression is 210 and sum of its first ( n-1) is 171 . If the first 3 then write the arithmetic progression.