MCQ
Statement A (Assertion) : A number is selected from the numbers 1 to 20 . The probability that it will be a prime is $\frac{2}{5}$.
Reason (R) : There exists 25 prime numbers from natural number 1 to 100 .
  • A
    Both assertion (A) and reason ( $R$ ) are true and reason (R) is the correct explanation of assertion (A).
  • Both assertion (A) and reason ( $R$ ) are true and reason $(R)$ is not the correct explanation of assertion (A).
  • C
    Assertion $(A)$ is true but reason $(R)$ is false.
  • D
    Assertion (A) is false but reason $(R)$ is true.

Answer

Correct option: B.
Both assertion (A) and reason ( $R$ ) are true and reason $(R)$ is not the correct explanation of assertion (A).
(b):Clearly, Reason is true.
Now, total number of outcomes $=20$
Favourable outcomes are $\{2,3,5,7,11,13,17,19\}$ i.e., 8 in number.
$\therefore \quad$ Required probability $=\frac{8}{20}=\frac{2}{5}$
$\therefore \quad$ Assertion and Reason both are true but Reason is not the correct explanation of Assertion.

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

Directions: In the following questions, a statement of assertion $(A)$ is followed by a statement of reason $(R)$ .Mark the correct choice as:
Assertion: If the length of shadow of a vertical pole is equal to its height, then the angle of elevation of the sun is $45^{\circ}$
Reason: According to pythagoras theorem, $h ^2= I ^2+ b ^2$ where $h =$ hypotenuse, $I =$ length and $b =$ base
Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : If we number is added to its own $- \text{ve}$ number then the result is zero is known as additive inverse.
Reason : $3 + (-3) = 0$ is additive inverse.
Statement A (Assertion): In the circumferences of two circles are in the ratio $1: 3$, then the ratio of their areas is $1: 9$.
Statement R (Reason) : The area of a sector of a circle of radius $r$ with sector angle $\theta$ is $\frac{\theta}{180^{\circ}} \times \pi r^2$ sq. units.
Statement-1 (A): In Fig. O is the centre of a circle and $P Q$ is a chord. If the tangent $P R$ at $P$ makes an angle of $50^{\circ}$ with $P Q$, then $\angle P O Q=100^{\circ}$.
Statement-2 (R): A tangent to a circle is perpendicular to the radius through the point of contact.
Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : Additive inverse of real no. is $8.$
Reason : Additive inverse of $5$ is $8.$
Statement-1 (A): The sum of $n$ terms of the series $\sqrt{5}+\sqrt{20}+\sqrt{45}+\sqrt{80}+\ldots$ is $\frac{\sqrt{5}}{2} n(n+1)$.
Statement-2 (R): The sum of first $n$ natural numbers is $\frac{n(n+1)}{2}$.
Statement-1 (A): Let $a, b$ be non-zero real numbers. Then, $\sec ^2 \theta=\frac{4 a b}{(a+b)^2}$ is true if and only if $a=b$.
Statement-2 (R): $\sec ^2 \theta \geq 1$ for $0 \leq \theta<90^{\circ}$.
Statement-1 (A): For $0<\theta \leq 90^{\circ}, \sin \theta+\operatorname{cosec} \theta \geq 2$.
Statement-2 (R): $\quad x+\frac{1}{x} \geq 2$ for all $x>0$.
Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : Cube root of $9$ is a surd.
Reason : $9$ is rational and cube root of $9$ is irrational.
Directions : In the following questions, the Assertions $(A)$ and Reason $(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : Common difference of an $AP$ in which $a _{21}- a _7=84$ is $14$.
Reason : $n$ th term of $AP$ is given by $a _{ n }= a +( n -1) d$