Answer:
87km
Step-by-step explanation:
Volume is proportional to radius cubed, so radius is proportional to the cube root of volume.
Increase volume by a factor of 10^6 and radius increases by a factor of the cube root of 10^6, which is 10^(6/3) = 10^2 = 100.
100 * 0.87 km = 87 km
