A coin is tossed once. The probability of getting a tail is :

1. 1

2. 2

3. $\dfrac{1}{2}$

4. none of these

When a coin is tossed, each toss has 2 possible outcomes : head (H) or tail (T).

The number of possible outcomes when a coin is tossed n times = 2ⁿ

For this case, n = 1

So, 2¹ = 2

The number of possible outcomes when a coin is tossed once is 2.

Number of favourable outcomes (Getting tail (T)) = 1

P(Getting tail (T)) = $\dfrac{\text{Number of favourable outcomes}}{\text{Total number of outcomes}}$

= $\dfrac{1}{2}$

Hence, option 3 is the correct option.