MCQ
Let $S_n$ denote the sum of the first $n$ terms of an $A.P$.. If $S_4 = 16$ and $S_6 = -48$, then $S_{10}$ is equal to
- A$-410$
- B$-260$
- ✓$-320$
- D$-380$
✓
Answer
Correct option: C.
$-320$
c
$2\left\{ {2a + 3d} \right\} = 16$
$2\left\{ {2a + 3d} \right\} = 16$
$3\left\{ {2a + 5d} \right\} = - 48$
$2a + 3d = 8$
$2a + 5d = - 16$
$d = - 12$
${S_{10}} = 5\left\{ {44 - 9 \times 12} \right\}$
$ = - 320$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The graph of $y = ax^2 + bx + c$ is shown. Which of the following does $NOT$ hold good?
→Which of the following is not a statement?
Choose the correct answers from the given four option: Let S = {x | x is a positive multiple of 3 less than 100} P = {x | x is a prime number less than 20}. Then n(S) + n(P) is.
A quadratic polynomial $ y = f (x)$ with absolute term $3$ neither touches nor intersects the abscissa axis and is symmetric about the line $x = 1$ . The coefficient of the leading term of the polynomial is unity. A point $A(x_1, y_1)$ with abscissa $x_1 = 1$ and a point $B(x_2, y_2) $ with ordinate $y_2 = 11 $ are given in a cartisian rectangular system of co-ordinates $OXY $ in the first quadrant on the curve $y = f (x)$ where $ 'O'$ is the origin. The graph of $y = f(x)$ represents a parabola whose focus has the co-ordinates
→If $P\,(A) = \frac{1}{4},\,\,P\,(B) = \frac{5}{8}$ and $P\,(A \cup B) = \frac{3}{4},$ then $P\,(A \cap B) = $
→The number of words from the letters of the word 'BHARAT' in which B and H will never come together, is:
Choose the correct answer. A plane is parallel to yz-plane so it is perpendicular to:
$\frac{{\sqrt 2 - \sin \alpha - \cos \alpha }}{{\sin \alpha - \cos \alpha }} = $
→A six faced dice is so biased that it is twice as likely to show an even number as an odd number when thrown. It is thrown twice. The probability that the sum of two numbers thrown is even, is
The value of $\mathop \sum \limits_{k = 1}^{10} \left( {\sin \frac{{2k\pi }}{{11}} + i\cos \frac{{2k\pi }}{{11}}} \right)$ is
→