Answer:
The Qn aint correct
it would make more sense if the figures invested where different
8% of 19k + 9% of 19k =1620
the figures are the same so even if we shifted the first 19k to the second side of 9% still it could make no sense(remain the same)
So volue of a cone=area of circle base times heigt times 1/3
height=4
area of base=pi times r^2
area of abse=aprox 3.14 times 3.2^2=32.1536
32.1536 times 4 times 1/3=32.1536 times 4/3=42.87 the amount of sand is 42.9 ft^3