For an A.P. `T_(10) = 1/20 , T_20 = 1/10`. Find sum of first 200 term.

In the A.P. nth term of an A.P. is given by (-4n + 15). Find the sum of first 20 terms of A.P.

For an A.P., t_( 1) = 25 and t_(20) = 405 . Find the common difference.

In an A.P., if T_(1) +T_(5)+ T_(10) +T_(15)+ T_(20) + T_(24) = 225, find the sum of its 24 terms.

In an A.P., if T_(1) +T_(5)+ T_(10) +T_(15)+ T_(20) + T_(24) = 225, find the sum of its 24 terms.

the A.P. nth term of an A.P. is given by (-4n+15). Find the sum of first 20 terms of A.P.

If t_(n) represents nth term of an A.P., t_(2)+t_(5)-t_(3)= 10 and t_2 + t_9= 17. find its first term and its common difference.

If t_r denotes the r^(th) term of an A.P. and t_1+ t_5 + t_10 + T_15 + t_20 + t_24 = 75 , then sum of its first 24 terms is :

If t_r denotes the r^(th) term of an A.P. and t_1+ t_5 + t_10 + T_15 + t_20 + t_24 = 75 , then sum of its first 24 terms is :

If the second term and the fourth terms of an A.P. are 12 and 20 respectively, then find the sum of first 25 terms: