Lesson: Using Permutations to Find Probability

Ethan, Jacob, and three of their coworkers each take the bus to work. If they each have an equal chance of arriving first, determine the probability of Jacob arriving first and Ethan arriving second.

A small combination padlock can be opened by entering three different specified numbers from 1 to 9 in a specified order. Benjamin has 10 attempts to guess the combination. Determine the probability of him opening the lock.

Two people are chosen randomly from a group of six hundred two. What is the probability that Benjamin was selected first and Ethan second?