What is the sum of the first 13 terms of an arithmetic progression if the first term is -10 and last term is 26?

Find the n<sup>th</sup> term of the following sequence :</br> 5 + 55 + 555 + . . . . T<sub>n<…

If S<sub>n</sub> denote the sum of the first n terms of an A.P. If S<sub>2n</sub> = 3S<sub&gt…

The 9<sup>th</sup> term of an A.P. is 449 and 449<sup>th</sup> term is 9. The term which is equa…

A boy agrees to work at the rate of one rupee on the first day, two rupees on the second day, and four rupees on third d…

Two A.P.’s have the same common difference. The first term of one of these is 8 and that of the other is 3. The di…

If 7<sup>th</sup> and 13<sup>th</sup> terms of an A.P. be 34 and 64 respectively, then its 18&lt…

Find the first term of an AP whose 8<sup>th</sup> and 12<sup>th</sup> terms are respectively 39 …