A biker covered half the distance between two towns in 2 hr 30 min. After that he increased his speed by 2 km/hr. He covered the second half of the distance in 2 hr 20 min. Find the distance between the two towns and the initial speed of the biker. Choose the correct choice from the following options:
A) 140
B) 120
C) 130
D) 150
E) 160

Rationale: let x km / hr be the initial speed of the biker , then his speed during the second part of the trip is x + 2 km / hr . half the distance between two cities equals 23060 ⋅ x km and 22060 ⋅ ( x + 2 ) km . from the equation : 23060 ⋅ x = 22060 ⋅ ( x + 2 ) we get x = 28 km / hr . the intial speed of the biker is 28 km / h . half the distance between the two towns is 2 h 30 min × 28 = 2.5 × 28 = 70 . so the distance is 2 × 70 = 140 km . answer is a .
Answer: A