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.