Two cars start at the same point driving in opposite directions. The slower car travels 50mph and stops 30 minutes before the faster car. The faster car travels 65 mph and stops once the two cars are 665 miles apart. How long after they start driving are the cars 665 miles apart?

If an object travels at five feet per second, how many feet does it travel in one hour?

Samuel randomly must guess a secret code. Codes contain 4 letters that can be reused. What is the probability that Samuel guesses the correct secret code if he has only one guess?

A secret code contains 3 digits followed by 2 letters. If digits cannot be reused but letters can be reused, how many codes can be formed?

A secret code contains 5 digits. If digits can be reused, how many codes could be made?

The proportion of students who receive an A is about 15%. In a group of 180 students what is the mean number of As? If you select 4 students what is the probability they all do not have As?