Question

Check these math questionsThanks soo much!!

Answer 1

Problem One

The volume of a cone is

V= 1/3 * pi * r^2 * h

h = 20  so

V = 1/3 * pi * r^2 * 20        Multiply by 3

3V = pi * r^2 * 20              Divide by 20*pi

3V/(20*pi) = r^2                Take the square root of both sides.

√(3V/(20*pi) ) = √r^2        Switch

√r^2 = √(3V/(20*pi) )

r =  √(3V/(20*pi) )

A is wrong because it is taking the cube root to find r. Only the square root is needed.

C is wrong because the right side is a square root, not squared.

D is wrong because it is the reciprocal (up side down) of the answer.

The answer is B.

Problem Two

Before  you do anything else, find out what she charges for 1 dog.

27  dogs = 324

1    dog = x          Cross multiply

27x = 324           Divide by 27

x = 324 / 27        Do the division

x = 12 dollars for 1 dog.

Now you can look at the graph. Plot the following points (x < 16)

Number dogs        Amount

1                               12

3                              36

5                              60

That's enough to get the line which I've given you below.

Answer 2

1st Question :

We know that Volume of Cone is given by : $\frac{\pi r^2h}{3}$

Given the height of the Cone : 20 inches

$\implies v = \frac{20\pi r^2}{3}\\\\\implies 3v = 20\pi r^2\\\\\implies r(v) = \sqrt{\frac{3v}{20\pi}}$

2nd Question :

Given that : the amount of money jeannine earns varies directly with the number of dogs she bathes.

⇒ y ∝ x

let us find the money jeannine gets for one dog wash.

⇒ $\frac{y_1}{y_2} = \frac{x_1}{x_2}$

⇒ y₁ = 324 and x₁ = 27 and x₂ = 1

$\implies \frac{324}{y} = \frac{27}{1}\\\\\implies Amount\;for\;one\;dog = \frac{324}{27} = 12$

So , The Equation is : y = 12x