Speed of the cycle = 6 km / hr
Distance travelled to reach her Aunt’s house = 12 km
∴ Time requried = (Distance travelled)/Speed
= 2 hours
Let the time required when the speed of the cycle is 4 k,/hr be x hours.
The speed of the cycle and the time required to the travel the same distance are in inverse proportion.
∴ 4 × x = 6 × 2
∴ x = (6 x 2)/4 = 3 hours
∴ Mary will require 2 hours if she is cycling at 6 km/hr and 3 hours if she is cycling at 4 km/hr to reach her Aunt’s house.
