The way to get from Earth directly to another planet that lets you use the smallest rocket engines
and the least fuel (and thereby lets you do it at lowest cost) is to use a Hohmann transfer orbit. This is an elliptical orbit with the Sun at one focus and which just touches the orbit of the Earth and the destination planet as shown. The rockets are only fired for a short time when leaving Earth and when arriving at the destination planet: the rest of the time the spacecraft just coasts like a planet orbiting the Sun. Note that in this drawing Earth and Jupiter both orbit in the counterclockwise direction.
(Hint: this involves one of Kepler's Laws.) Consider a flight from the Earth to Jupiter. How long does it take to go from Earth to Jupiter? Assume the planetary orbits are circular. The semimajor axis of Jupiter's orbit is 5.20 AU.
a. 1.10 years
b. 1.59 years
c. 2.22 years
d. 2.73 years
e. 4.91 years