What is the probability of getting heads twice in a row?

The probability of getting heads twice in a row is 1 in 4, or 25%.

To understand this, let's break it down. When you flip a fair coin, there are two possible outcomes: heads (H) or tails (T). Each outcome has an equal probability of occurring, which is 1/2 or 50%. When you flip the coin twice, the outcomes of each flip are independent of each other. This means the result of the first flip does not affect the result of the second flip.

To find the probability of getting heads twice in a row, you need to multiply the probability of getting heads on the first flip by the probability of getting heads on the second flip. Since each flip has a probability of 1/2, you calculate it as follows:

\[ \text{Probability of heads on first flip} = \frac{1}{2} \]
\[ \text{Probability of heads on second flip} = \frac{1}{2} \]
\[ \text{Combined probability} = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \]

So, the probability of getting heads twice in a row is 1/4, which can also be expressed as 0.25 or 25%. This means that if you were to flip a coin twice many times, you would expect to get heads twice in a row about 25% of the time.