Two ships on the equator are on longitudes 45oW and 45oE respectively. How far are they apart along the equator, correct to 2 significant figures? (Take the radius of earth = 6400km and π = 22/7)

A. 15,000km
B. 10,000km
C. 6,400km
D. 5,000km
E. 3,200km

Correct Answer: Option B

B. 10,000km

D = θ/360 x 2πR
45 + 45/360o
x 6400

= 10057 ≅ 10000km