Answer
1.5 hr
Work Step by Step
90 min = hr
Use a unit fraction with hour (the unit for your answer) in the numerator, and minute (the unit being changed) in the denominator.
Because 60 minute (min) = 1 hour (hr), the necessary unit fraction is
(1 hour)/(60 minute)
Multiply 90 times the unit fraction.
90 * (1 hour)/(60 minute) = 3/2 hr= 1.5 hr