Someone is asked to select a number from $1$ to $100$. The probability that the selected number is a prime number is:
(a) $\dfrac{1}{4}$
(b) $\dfrac{13}{50}$
(c) $\dfrac{27}{100}$
(d) $\dfrac{23}{100}$
Step-by-Step Solution
Key Concept: There are $25$ prime numbers between $1$ and $100$. $P = \dfrac{25}{100} = \dfrac{1}{4}$.
25 primes from 1 to 100 $\Rightarrow P = 25/100 = 1/4$. [1.0 Mark]
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🎯 Official CBSE Marking Scheme:
Evaluating $1/4$: 1.0 Mark
Correct Answer: $\dfrac{1}{4}$