Question

a gardener will fill a plot that is 4 inches deep,30 feet long and 10 feet wide with colourful cypress mulch.if the mulch costs $1.50 per cubic foot,how much will it cost the gardener to fill the entire plot? in dollars

Answer 1

volume of the plot below Earth's surface in the neighborhood:
           =       (4/12)' * 30' * 10'  = 100 feet³

   cost = volume of mulch required * price
            =  100 cubic ft * $1.50/ cubic ft = $ 150

Answer 2

l=30ft
b=10ft
h=4''=4*0.0833ft=0.3332ft
.
So the total vol. of the plot=30X10X0.332 ft³
Total cost=1.50X30X10X0.332=$149.4