Yep, use the formula , which means "distance equals rate times time"
The distance is what you don't know, the rate is the rate of speed given as 55 miles per hour, and the time is given as 3.5 hours, so:
You can push calculator buttons as well as I can. There is no indication of the required precision for your answer, so, unless otherwise instructed, I would round your answer to the nearest whole number mile. That is because the least precise measurement in the given data is to the nearest whole number of miles per hour. Rule of thumb is to never give the results of a calculation to a precision greater than the least precise input measurement.
