Question

Which of the following can not be the probability of an event ?

• A. $\frac{39}{100}$
• B. $\frac{0.001}{20}$
• C. $\frac{10}{0.2}$
• D. $10\%$

Hint:

Always simplify fractions and percentages first.
Any value greater than $1$ (or $100\%$) or less than $0$ can never represent a probability.

Answer 1

The Correct Option is C

Step 1: Recall the valid range for probability.
Any probability must satisfy $0 \le P(E) \le 1$, which is the same as saying it must lie between $0\%$ and $100\%$.
Step 2: Convert every option to a percentage.
Option (A): $\frac{39}{100} = 39\%$. Option (B): $\frac{0.001}{20} = 0.005\%$. Option (C): $\frac{10}{0.2} = 50$, which is $5000\%$. Option (D) is already $10\%$.
Step 3: Spot the value outside the valid range.
Only option (C) exceeds $100\%$, so it cannot represent a probability.
\[ \boxed{\frac{10}{0.2}} \]