Answer:
Speed of the bicycle is 6.96 miles per hour.
Step-by-step explanation:
Diameter of the wheel = 26 inches
Rotation of the wheel = 90 revolution per minute
We have to calculate the speed of the bicycle.
Since in one rotation distance moved by the bicycle = circumference of the wheel
Distance traveled in one rotation = 2πr
= 
= 2×3.14×13
= 81.64 inch
Since rotation of the wheel is = 90 revolutions per minute
Therefore, speed of the bicycle = 90×81.64 inches per minute
= 7347.6 inches per minute
Since 1 inch =
miles
Therefore, 7347.6 inches =
miles
= 0.116 miles per minute

= 6.96 miles per hour
Therefore, Speed of the bicycle is 6.96 miles per hour.