mike charges 100 dollars service charge plus 65 dollars per hour.
amy charges 40 dollars service charge plus 80 dollars per hour.
the cost to repair from mike is 100 + 65 * x.
the cost to repair from amy is 40 + 80 * x.
let x = 3 and you get:
the cost to repair from mike is 100 + 65 * 3 = 295 dollars.
the cost to repaid from amy is 40 + 80 * 3 = 280 dollars.
as long as the time to repair is 3 hours or less, the cost to repair will be cheaper from amy.
Given a N quantity of numbers, the Geometric Mean is equal to the N-th root of product of the N numbers
In this case, we have two numbers, then we need to multiply them and take square root:
![\sqrt{40\cdot15}=\sqrt[]{600}=\sqrt[]{100\cdot6}=\sqrt[]{100}\cdot\sqrt[]{6}=10\sqrt[]{6}](https://tex.z-dn.net/?f=%5Csqrt%7B40%5Ccdot15%7D%3D%5Csqrt%5B%5D%7B600%7D%3D%5Csqrt%5B%5D%7B100%5Ccdot6%7D%3D%5Csqrt%5B%5D%7B100%7D%5Ccdot%5Csqrt%5B%5D%7B6%7D%3D10%5Csqrt%5B%5D%7B6%7D)
The answer is:
10√6
Rounded is Approximately 24.5
X=6y
sum of their reciprocals
(1/x)+(1/y)=7
x=6y
1/6y+1/y=7
1/6y+6/6y=7
7/6y=7
times both sides by 6y
7=42y
divide both sides by 42
1/6=y
x=6y
x=6(1/6)
x=6/6
x=1
the numbers are 1 and 1/6
