Agrape and apple and a watermelon are arranged at the corners of a triangle so that each piece of fruit is three meters away from the other two the gravatational force between which two pieces of fruit will be the greateset

-- There are three pairs of mass with gravitational forces between them.

-- The distances between the masses are the same for each pair.

-- The only other quantity that determines the strength of the gravitational
force is the product of the masses.

-- The product of the masses is greatest for the apple and the watermelon,
so the strength of the gravitational force between them is the greatest.