Answer
$\frac{1}{3}$
Work Step by Step
The probability that the friend is late between 15 and 25 minutes is:
$\frac{1}{30} \times (25 - 15) = \frac{1}{30} \times 10 = \frac{1}{3}$
The probability for every minute is $\frac{1}{30}$ because that the value of the the random variable is between 0 and 30.
