Consider two people being randomly selected. What is the probability that two people were born on Friday?how can i solve this?
The probability that person 1 is born on a Friday is:
$\displaystyle P(X_1=F) = \frac{1}{7}$
and the probability that person 2 is born on a Friday is:
$\displaystyle P(X_2=F) = \frac{1}{7}$
so both would be $\displaystyle P(X_2=F) \times P(X_1=F) = \frac{1}{7} \times \frac{1}{7} = \frac{1}{49}$