 
 <translate> The volume of the slab is 100 * 100 * .5 = 5000 cubic feet. So it weighs 5000 * 150 = 750000 pounds. That means the cost is 750000 * $0.02 = $15,000 per house. So the total cost for all 3 houses is $15000 * 3 = $45,000.
Thus, the answer is 45000. <ibo> Mpịakọta nke slab ahụ bụ 100 * 100 *.5 = 5000 cubic feet. Ya mere, ọ dị arọ 5000 * 150 = 750000 pound. Nke ahụ pụtara na ọnụ ahịa ya bụ 750000 * $0.02 = $15,000 kwa ụlọ. N'ihi ya, ngụkọta ego nke ụlọ atọ ahụ bụ $15000 * 3 = $45,000. Ya mere, azịza ya bụ 45000. 