The sum of $3+5+7+\ldots$ to $n$ terms is:

What is the sum of all integers between $81$ and $719$ that are divisible by $5$?

If the sum of the first $n$ terms of the series $\sqrt{3} + \sqrt{75} + \sqrt{243} + \sqrt{507} + \dots$ is $435\sqrt{3}$,then $n$ equals:

$A$ man saves $200$ in each of the first three months of his service. In each of the subsequent months,his saving increases by $40$ more than the saving of the immediately previous month. His total saving from the start of service will be $11040$ after ............ months.

Which term of the sequence $(-8 + 18i), (-6 + 15i), (-4 + 12i), \dots$ is purely imaginary (in $^{th}$)?

If the first,second and last terms of an $A.P.$ are $a, b$ and $2a$ respectively,then its sum is: