It is given in the question that a mile equals 1.609 km and the moon is 2,160 miles in diameter.
One mile is equal to 1.609 km. Therefore 2160 mile equals to
[tex] 2160*1.609 km = 3475.44 km [/tex]
THerefore 2160 mile equal to 3475.44 km and hence the diameter of the moon is 3475.44km .