Which of the following cannot be probability of any event ?

Options

A. `(3)/(4)`
B. 0.25
C. `0.5`
D. `-3.4 `

Answer

To determine which of the given options cannot be a probability of any event, we need to remember the basic rule of probability:

**Step 1: Understand the range of probability.**
The probability of any event must lie between 0 and 1, inclusive. This means:
- The minimum value of probability is 0 (indicating an impossible event).
- The maximum value of probability is 1 (indicating a certain event).

**Step 2: Evaluate each option.**
Let's evaluate the given options one by one.

**Option 1: 3/4**
- Convert 3/4 to decimal:
\[ \frac{3}{4} = 0.75 \]
- Check if 0.75 lies between 0 and 1:
\[ 0 < 0.75 < 1 \]
- Conclusion: This is a valid probability.

**Option 2: 0.25**
- Check if 0.25 lies between 0 and 1:
\[ 0 < 0.25 < 1 \]
- Conclusion: This is a valid probability.

**Option 3: 0.5**
- Check if 0.5 lies between 0 and 1:
\[ 0 < 0.5 < 1 \]
- Conclusion: This is a valid probability.

**Option 4: -3.4**
- Check if -3.4 lies between 0 and 1:
\[ -3.4 < 0 \]
- Conclusion: This is NOT a valid probability.

**Final Answer:**
The option that cannot be a probability of any event is **-3.4**.

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