As a result of his observations, Roemer concluded that eclipses of Io by Jupiter were delayed by 22 min during a 6 month period as the Earth moved from the point in its orbit where it is closest to Jupiter to the diametrically opposite point where is is farthest from Jupiter. Using 1.50 x 10^8 as the average radius of the Earth's orbit around the Sun, calculate the speed of light from these data. I have absolutely no idea how to start this. Please give me some suggestions. Thank you.