Distance of earth from sun is the Earth’s orbital radius;
re = 1.5 × 108 km
= 1.5 × 1011 m
Time period of Earth = Te
Time period of Saturn = (29.5 × Te)
From Kepler’s 3rd Law of planetary motion
T2 ∝ R3
= (29.5)2 × (1.5 × 1011)3
rs = (29.5)2/3 × 1.5 × 1011
= 1.432 × 1012 m.