What is the probability of getting 2 heads if you flip a coin 3 times.

To solve this problem, we need to understand the concept of binomial probability.

Step 1: Identify the number of trials, the number of successful outcomes, and the probability of a successful outcome. In this case, we are flipping a coin 3 times (trials), we want to get 2 heads (successful outcomes), and the probability of getting a head in one flip is 0.5 (since a coin has 2 equally likely outcomes).

Step 2: Use the formula for binomial probability, which is:

P(X=k) = C(n, k) * (p^k) * ((1-p)^(n-k))

where:

• P(X=k) is the probability of k successes in n trials
• C(n, k) is the combination of n items taken k at a time
• p is the probability of success in a single trial
• n is the number of trials
• k is the number of successful outcomes

Step 3: Substitute the values into the formula:

P(X=2) = C(3, 2) * (0.5^2) * ((1-0.5)^(3-2))

Step 4: Calculate the combination C(3, 2). This is the number of ways you can choose 2 items from 3, which is 3.

Step 5: Substitute this back into the formula:

P(X=2) = 3 * (0.5^2) * (0.5^(3-2))

Step 6: Calculate the powers of 0.5:

P(X=2) = 3 * 0.25 * 0.5

Step 7: Multiply the results together:

P(X=2) = 0.375

So, the probability of getting 2 heads when flipping a coin 3 times is 0.375, or 37.5%.