The sums of n terms of two A.P.s are in the ratio (5n + 4): (9n + 6). Find the ratio of their `18^(th)` terms.

The sum of n terms of two arithmetic progressions, are in the ratio (3 n+8):(7 n+15) . Find the ratio of their 12^ (th) terms.

The ratio between the sums to n terms of two AP is 7n+1:4n+27 . Find the ratio of their 11^th terms.

If the sum of n terms of an A.P is 3n^2+5n and its m^(th) term is 164. Find the value of m.

The ratio of the sums of m and n terms of an A.P is m^2:n^2 . Show that the ratio of m^(th) and n^(th) terms is (2m — 1): (2n — 1).

If the 9th term of an AP is zero, then the ratio of 29th term to 19th term is

Find the sum to n terms of the series whose n^(th) term is n(n+1)(n+4)

The ratio of the sums of m and n terms of an A.P is m^(2) :n^(2) . Show that the ratio of the mth and nth term is (2m-1) : (2n-1) .

Find the sum of n terms of the AP, whose K^th term is a_k=5K+1 .

Find the sum to n terms of a series is 7n^2-5n . Show that it is an AP and find the 15^th term.

Suppose that a, ar, ar^2,ar^3,ar^4,ar^5 are the first 6 terms of a G.P Find the ratio of the sum of the first tree terms and the sum of first 6 terms