SOLUTION: Frank drove 100 mi. For the first 55 mi he averaged 50 mph, and for the last 45 mi he averaged 30 mph. What was his average speed for the entire trip?

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Frank drove 100 mi. For the first 55 mi he averaged 50 mph, and for the last 45 mi he averaged 30 mph. What was his average speed for the entire trip?      Log On

Hi,

Note: this would be a weighted average

.55 of the trip at 50mph and .45 of the trip at 30mph

Average speed for trip = .55*50mph + .45*30mph = 27.5mph + 13.5mph  = 41mph