Is -18.75 a real number, irrational, rational, integer, whole or natural? it can be more than one choice

What is the exact volume of the cylinder (radius 13 in., height 30 in.)

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

The function a represents the cost of manufacturing product a, in hundreds of dollars, and the function b represents the cost of manufacturing product b, in hundreds of dollars. a(t) = 5t + 2 b(t) = 7t - 2t +4 find the expression that describes the total cost of manufacturing both products, a(t) + b(t). a. 7t^2 - 7t + 2 b. 7t^2 + 3 +6 c. 7t^2 + 7t - 6 d. 7t^2 - 3t + 6