Question

The value of y varies jointly with the values of x and z When x = 4 and z = 10, the value of y is 360.

What is the value of y when x 5 and z = 12?
A. 540
B. 9
C. 153
D. 450

Answer 1

A

Explanation:

Joint variation is given by:

`y=kxz`

Where k is some constant.

We are given that y = 360 when x = 4 and z = 10. Therefore:

`360=k(4)(10)`

Solving for k:

`40k=360\Rightarrow k=9`

Therefore, our equation is:

`y=9xz`

Then when x = 5 and z = 12:

`y=9(5)(12)=540`

The answer is A.