Which is the longer trip from earth, a one-way trip to mars or a round-trip to venus?

if a trip from earth to mars, is 97/186=.52150
 
and a trip from earth to venus is 0.2774(now we have to times it by 2 since its a roundtrip),

we get .5548 we can clearly see that .5548>.52150

So roundtrip venus

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.