Question

If a certain coin is flipped, the probability that the coin will land heads up is \small \frac{1}{2}. If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?

Answer 1

The probability of the heads up on the first three flips and not on the last two flips will be 1/32.

Explanation:

As, the probability of head up when one time coin is flipped is 1/2. And it is said in the question that you must get heads in the first three flips.

So, for the first three flips the probability is = (1/2)^3 = 1/8

And for the last two flips you want to get not heads up.

Then, the probability is = (1/2)^2 = 1/4

Hence, your overall probability will be = 1/8 × 1/4 = 1/32 .