A deck of 10 cards labeled 1–10 is shuffled. One card is selected at random. If the experiment is repeated 120 times, how many times will you expect to select number 5?

Question

1/10
1/120
12
10

Answer 1

To find out how many times you would expect to select the number 5 after 120 trials, you can use the concept of expected value.

Since there are 10 cards labeled from 1 to 10, the probability of selecting the number 5 on any single draw is:

\[ P(5) = \frac{1}{10} \]

If this experiment is repeated 120 times, the expected number of times you would select the number 5 is given by:

\[ \text{Expected number of selections} = P(5) \times \text{Number of trials} = \frac{1}{10} \times 120 = 12 \]

Thus, the expected number of times you will select the number 5 after 120 trials is 12.