The surface gravity of Mars is 3.7 m/s². On Earth it is 9.8 m/s². 3.7/9.8 = 38%.
So 38% of 120 lbs is 45 pounds.
Let AM be the distance between point A and the right wall and AN be the distance between A and the left wall.
Δ AMB is an isosceles right triangle and Δ ANC is half of an equilateral triangle.
Length of AM = 30 m. Length of AN = 1/2 · 80 = 40 m.
The distance between the walls is:
30 m + 40 m = 70 m.
You divide 47,000 by 8. You should get 5,875. That should be the answer