The first term of an $A.P.$ is $2$ and the common difference is $4$. The sum of its $40$ terms will be:

The sum of an infinite geometric series is $3$. $A$ series,which is formed by squares of its terms,has the sum also $3$. The first series is

The sum of the numbers between $100$ and $1000$ which are divisible by $9$ is:

Let $A$ be the sum of the first $20$ terms and $B$ be the sum of the first $40$ terms of the series $1^2 + 2 \cdot 2^2 + 3^2 + 2 \cdot 4^2 + 5^2 + \dots$. If $B - 2A = 100\lambda$,then $\lambda$ is equal to:

Three numbers are in $G.P.$ such that their sum is $38$ and their product is $1728$. The greatest number among them is

If the $p^{th}$ term of an $A.P.$ is $\frac{1}{q}$ and the $q^{th}$ term is $\frac{1}{p}$,then the sum of its $pq$ terms will be: