Consider a sequence whose sum of first $n$ -terms is given by $S_n = 4n^2 + 6n, n \in N$, then $T_{15}$ of this sequence is -
$118$
$120$
$122$
$86$
Three number are in $A.P.$ such that their sum is $18$ and sum of their squares is $158$. The greatest number among them is
If $2x,\;x + 8,\;3x + 1$ are in $A.P.$, then the value of $x$ will be
Which term of the sequence $( - 8 + 18i),\,( - 6 + 15i),$ $( - 4 + 12i)$ $,......$ is purely imaginary
The sum of $24$ terms of the following series $\sqrt 2 + \sqrt 8 + \sqrt {18} + \sqrt {32} + .........$ is
If the sum of $n$ terms of an $A.P.$ is $nA + {n^2}B$, where $A,B$ are constants, then its common difference will be