Lois rode her bike to visit a friend. she traveled at 10 mi/h. Her friend drove her home in a car traveling at 25 mi/h. Lois took 1.5 hours longer to go to her friend's than to return home. How many hours did it take Lois to ride to her friend's house?

Speed of Lois' bike = 10 miles/h

Speed of Lois' friend's car = 25 miles/h

Time taken by Lois to reach via car = t hours

Time taken by Lois to reach via bike = 1.5 + t

We know that the distance traveled in both the cases is the same

Hence, distance traveled by car = distance traveled by bike

⇒ Speed of car * time taken by car = Speed of bike * time taken by bike

⇒ 25 * t = 10 * (t+1.5)

⇒ 25t = 10t + 15

⇒ 15t = 15

⇒ t = 1

Hence, Lois took t + 1.5, i. e. 2.5 hours to reach his friend's house.