V =

r^2h/3
V = 3.14 x 4^2 x 6/3 (remember r is 1/2 of the diameter)
V = 3.14 x 16 x 2
V = 100.5
Please find the attached file for a better understanding of the explanation given here.
the attached diagram is a generated image of the first fifteen rows of a pascal's triangle. As can be seen from the image, the least four-digit number in the first fifteen rows of pascal's triangle is 1001.
In the diagram attached that number is present in the very last row and is highlighted using a yellow rectangle.
I = prt
where i = interest, p = principal, r = interest rate, t = time
i = $1500 * 0.07 * 1.5
i = $157.5