Question
Maximum value of sum of arithmetic progression $50, 48, 46, 44 ........$ is :-

Answer

d
For maximum sum $\Rightarrow \mathrm{T}_{\mathrm{n}}=0$

$a+(n-1) d=0$

$\Rightarrow 50+(n-1)(-2)=0 \Rightarrow n=26$

So $S_{26}=\frac{26}{2}[2 \times 50+25 \times(-2)]=650$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $a = i - j,b = i + j,\,\,\,c = i + 3j + 5k$  and  $n$ is a unit vector such that $b.n = 0,a.n = 0$ then the value of $|c\;.\;n|$ is equal to
Let $z$ and $w$ be two complex numbers such that $w=z \bar{z}-2 z+2,\left|\frac{z+i}{z-3 i}\right|=1$ and $\operatorname{Re}(w)$ has minimum value. Then, the minimum value of $n \in N$ for which $w ^{ n }$ is real, is equal to..........
If $3^{2 \sin 2 \alpha-1},14$ and $3^{4-2 \sin 2 \alpha}$ are the first three terms of an $A.P.$ for some $\alpha$, then the sixth term of this $A.P.$ is 
In a hotel, four rooms are available. Six persons are to be accommodated in these four rooms in such a way that each of these rooms contains at least one person and at most two persons. Then the number of all possible ways in which this can be done is. . . . . . . . 
The centres of two circles $C_1$ and $C_2$ each of unit radius are at a distance of $6$ units from each other. Let $P$ be the mid point of the line segment joining the centres of $C_1$ and $C_2$ and $C$ be a circle touching circles $C_1$ and $C_2$ externally. If a common tangent to $C_1$ and $C$ passing through $P$ is also a common tangent to $C_2$ and $C$, then the radius of the circle $C$ is
In a series of $2n$ observations, half of them equal to $a$ and remaining half equal to $-a$. If the standard deviation of the observations is $2$, then $|a|$ equals
Let $A=\left[\begin{array}{lll}1 & 0 & 0 \\ 0 & \alpha & \beta \\ 0 & \beta & \alpha\end{array}\right]$ and $|2 A|^3=2^{21}$ where $\alpha, \beta \in Z$, Then a value of $\alpha $ is
If $A$ is skew symmetric matrix of order $3$ and $X$ be another matrix of same order, then $|XA + AX^T|$ is (where $|P|$ denotes determinant of matrix $P$ )
The value of ${\log _3}\,4{\log _4}\,5{\log _5}\,6{\log _6}\,7{\log _7}\,8{\log _8}\,9$ is
The value of $\int_{-2}^{2}\left|3 x^{2}-3 x-6\right| d x$ is ...... .