Question 321557
Suppose it takes 3 days for a space vehicle to travel from earth to the moon.  About how long would it take the same vehicle traveling at the same speed to reach Mercury?

Moon--240,000 it takes 3 days
so in 1 day it travels 240000/3
=80,000 
8*10^4 /day
Mercury--57,000,000
..
5.7*10^7 is the distance of mercury.
it will take 
5.7*10^7 / 8*10^4
=712.5 days