Question

Please help, thanks! Ok so, you pick a card at random, put it back, and then pick another card at random. There are FIVE cards and they are numbered like this: 1, 2, 3, 4, 5. What is the probability of picking a number greater than 1 and then picking a number less than 2? Write the answer as a fraction or whole number. Thank you!

Answer 1

Answer:

$P(x > 1\ and\ x < 2) = \frac{4}{25}$

Step-by-step explanation:

Given

$S = \{1,2,3,4,5\}$

$n(S) = 5$

Required

$P(x > 1\ and\ x < 2)$

$P(x > 1\ and\ x < 2)$ is calculated as:

$P(x > 1\ and\ x < 2) = P(x > 1) * P(x < 2)$

Since it is a probability with replacement, we have:

$P(x > 1\ and\ x < 2) = \frac{n(x > 1)}{n(S)} * \frac{n(x < 2)}{n(S)}$

For x > 1, we have:

$x > 1 = \{2,3,4,5\}$

$n(x > 1) = 4$

For x < 2, we have:

$x < 2 = \{1\}$

$n(x < 2) = 1$

$P(x > 1\ and\ x < 2) = \frac{n(x > 1)}{n(S)} * \frac{n(x < 2)}{n(S)}$

becomes

$P(x > 1\ and\ x < 2) = \frac{4}{5} * \frac{1}{5}$

$P(x > 1\ and\ x < 2) = \frac{4}{25}$