Two friends decide to get together; so they start riding bikes towards each other. They plan to meet halfway. Each is riding at 6 MPH. They live 36 miles apart. One of them has a pet carrier pigeon and it starts flying the instant the friends start traveling. The pigeon flies back and forth at 21 MPH between the 2 friends until the friends meet. How many miles does the pigeon travel? Choose the correct choice from the following choices.
A) 54	B) 66	C) 68	D) 60	E) 63

Rationale: "e 63 it takes 3 hours for the friends to meet ; so the pigeon flies for 3 hours at 21 mph = 63 miles"
Answer: E