Answer:
45 miles
Explanation:
Let, the friend's village from Lucas' house is x miles away.
Now, It takes Lucas 3 hours to cycle from his home to his friend's village. But if he travels 5 mph slower, it will take him 1.5 hours longer.
So, we can write

⇒ x = 1.5x - 22.5
⇒ 0.5x = 22.5
⇒ x = 45 miles (Answer)