Sequence

Q.

The nth term of the sequence 1, 3, 7, 15, ... can be written as

1. + 1

2. - 1

3. - 1

4. + 1

Q. Which number would replace the question mark in series
7, 12, 19, ?, 39

1. 24
2. 31
3. 26
4. 28

Q. Which of the following sequence is an arithmetic sequence

1. f(n) = $k{r}^n,$ n ∈ N
2. f(n) = (an + b) $k{r}^n,$, n ∈ N
3. f(n) = $\frac{1}{a(n+\frac{b}{n})};$ n ∈ N
4. f(n) = an + b; n ∈ N

Q. p^th term of the series $(3-\frac{1}{n})+(3-\frac{2}{n})+(3-\frac{3}{n})+....$ will be

1. $(3+\frac{P}{n})$
2. $(3-\frac{P}{n})$
3. $(3+\frac{n}{P})$
4. $(3-\frac{n}{P})$

Q. Which of the following sequence is an arithmetic sequence

1. f(n) = $\frac{1}{a(n+\frac{b}{n})};$ n ∈ N
2. f(n) = $k{r}^n,$ n ∈ N
3. f(n) = (an + b) $k{r}^n,$, n ∈ N
4. f(n) = an + b; n ∈ N

Q. Which term of the sequence (-8 + 18i), (-6 + 15i), (-4 + 12i), ....is purely imaginary

1. 5^th

2. 6^th

3. 8^th

4. 7^th

Q. The sequence $\frac{5}{\sqrt{7}},\frac{6}{\sqrt{7}},\sqrt{7},$ ....... is

1. H.P.

2. G.P.

3. A.P.
4. None of these

Q. A sequence is defined by $a_n=\frac{n^2-1}{n+1}$. The difference of its 1000th and 900th term is

1. 100
2. 200
3. 300
4. 1

Q. An ordered set of number defined as $\left(a_n:a_n=n^2+1,wheren\in N,n<10\right\}$forms a sequence.

1. True
2. False

Q. Let $N=\alpha \alpha \alpha \alpha \alpha \alpha$ be a $6$ digit number (all digits repeated) and $N$ is divisible by $924$ and let $\alpha ,\beta$ be the roots of the equation $x^2-11x+\lambda =0$. If the products of all possible values of $\lambda$ is $168k$, then value of $k$ is