Knowing that the Earth's diameter is about "3 2/3" times the diameter of the moon, what is the angular diameter of the Earth as seen by an observer on the moon?
You need a little more information, e.g. that the angular diameter subtended by the moon from Earth is about
Given this, the angular diameter of the Earth from the moon is approximately:
#31 * 11/3 = 341/3 ~~ 114'#or #1^@54'#