The highway patrol uses the following formula to estimate the speed (s), in miles per hour, at which a car was traveling if the car skidded d feet before stopping after the brakes were applied:

The variable f relates to the friction of the road surface. The following table estimates f for certain types of road surfaces and conditions.

If a car skids 80 feet on wet gravel, what is the approximate speed, in miles per hour, at which the car was traveling?

Dana works four 10-hour days during the week and is off every Friday. If the first Friday of the month falls on the 3rd, which of the following dates during that month will also be a Friday?

Boxes for shipping telephones can contain a maximum of 18 phones. What is the FEWEST number of boxes needed to ship an order for 110 phones?

Hattie, the manager of Speedy Burgers, wants to know the average amount of time it takes customers to order once they reach the counter. Hattie recorded these ordering times in seconds: 45, 52, 64, 87, 56, 21, 34, 49, 55, 29, 36. What was the mean (average) time in seconds it took customers to order?

Because correcting errors reduces the actual number of words per minute a person might type, some people use the following formula to calculate effective typing speed (T) in words per minute:

Where w is the number of words typed in 5 minutes, and e is the number of errors made.
If Cesar types 325 words in 5 minutes and makes 5 errors, what would be the value of T?