What is the circumference of a circle in which a 5 by 12 rectangle is inscribed?
13pi. The length of a diagonal of a 5 by 12 rectangle is 13 (pythagorean theorem). The diagonal of the rectangle is the diameter of the circle inscribed, and C = 2(pi)r.
The height h of a cylinder equals the circumference of the cylinder. In terms of r, what is the volume of the cylinder?
2pi2r3
For the system what is the value of x:
x+y=-9
x+2y=-25
7
Working alone, Bill takes three times the amount of time to paint a fence that Mike takes. If Bill and Mike work together, they can paint the fence in 2 hours. If Mike works at the same rate as when he worked with Bill, how long would it take Mike working alone to paint the same fence?
2 hours and 40 minutes. If x represents the number of hours it takes Mike working alone to paint the fence, then 3x is the number of hours it takes Bill working alone to paint the fence. So 2(1/x) + 2(1/3x) = 1 gives x=8/3 hours.
For the system of three equations: x-z=7, x+y=3, z-y=6, what is x?
8