The sun and a planet with a period of 5 years would have a distance of

To solve the problem shown above you must apply the proccedure shown below:

 1. You must apply the Kepler's third law, as below:

 (T1/T2)²=(R1/R2)³

 T1 and T2 are the orbital periods. (T1=1 year; T2=5 years)
 R1 and R2 are the orbital radius. (R1=1 Astronomical unit)

 2. Now, you must substitute the values shown above into the formula and clear R2:

 (1/5)²=(1/R2)³
 1/25=1/R2³
 R2³/25=1
 R2³=25
 R2=∛25
 R2=2.92 AU

 Therefore, the answer is: 2.92 AU