It is a GP. with r = 2, ie \begin{aligned} 2^1, 2^2, 2^3... \end{aligned}
If number of terms is n. Then,
\begin{aligned} 2 \times 2^{n-1} = 1024 \end{aligned} =>
\begin{aligned} 2^{n-1} = 512 \end{aligned}
or \begin{aligned} 2 \times 2^{n-1} = 2^9 \end{aligned}
so n-1 = 9 => n = 10
3. Which of the following is a prime number
9
2
4
8
Answer: Option B
Explanation:
A prime number is a natural number greater than 1 which has no positive divisors other than 1 or itself.
So from above options 2 is that number
4. What is the unit digit in
\begin{aligned}
(6324)^{1797} \times (615)^{316} \times (341)^{476}
\end{aligned}
1
5
7
0
Answer: Option D
5. There are four prime numbers written in ascending order. The product of first three is 385 and that of last three is 1001. The last number is: