120/90 = 1hour 20minutes , with no wind .
45 hours.
56
90 seconds
2 hours 15 minutes
A long time. Generally you should be doing situps "until failure."
How long dose it take to go 20 miles at 90 mph
He didn't do situps, silly!
90 days.
the prediction is about 90 ears
90 days
It is: 153/90 = 1.7 hours
60 to 90 days
It takes at most 90 minutes
90 hours of walking.
It would depend on your speed
90 months ... sorry!