Question

Ross drove 300 miles at r miles per hour and 360 miles at r+10 miles per hour. If the time needed to drive 300 miles was equal to the time needed to drive 360 miles, find the rates at which Ross drove (Express the time needed for each part of the trip as t=d/r)

Answer 1

For the 300 mile part:
t = d/r
t = 300/r

For the 360 mile part:
t = d/r
t = 360/(r + 10)

The times were equal, so

300/r = 360/(r + 10)

360r = 300(r + 10)

360r = 300r + 3000

60r = 3000

r = 50

r + 10 = 60

He drove 300 miles are 50 mph and 360 miles at 60 mph.
He drove