Rate time distance

Question

Keegan started biking to the internet cafe traveling 12 mph, after some time the bike got a flat so Keegan walked the rest of the way, traveling 5 mph. If the total trip to the internet cafe took 7 hours and it was 63 miles away, how long did Keegan travel at each speed?

_____hours at 12mph

_____hours at 5mph

Answer 1

d=rt, distance = speed times time traveled

12x + 5(7-x) = 63

12x - 5x = 63 -35 = 28

7x = 28

x = 28/7 = 4 hours on the bike at 12mph

7-x= 3 hours walking at 5mph