One cubic feet of sand wounds 100 lbs. A square sandbox with 5 foot sides had half of a foot of sand in it. How many lbs of sand is in the sandbox?

Ok so find volume of sandbox

v=area of base times height

height=1/2

area of base=a square=side^2=5^2=25

so

v=1/2 times 25=12.5 ft^3

12.5 cubic feet

1 cubic foot=100lb

12.5 times 1cubic foot=100lb times 12.5

12.5 cubic feet=1250lb

answer is 1250 lb