I wish to submit another problem in my series of Shell Games however I must confess I'm baffled at finding the correct solution. Therefore I am asking for suggestions on how to proceed.
The problem is an advancement on Shell Game 1 and 2.
A triangular pyramidic vault with edges of 10 ft. has steel walls and floor 6 inches thick. What is the volume of the steel to the nearest 0.1 cu. ft.?