Question

Question text
Which volume formula or formulas show(s) a joint variation?

I V=8^3

II V=πr^2h

III V=Bh

Select one:
a. III only
b. I only
c. II and III only
d. I, II, and III

Answer 1

1. V = s3 
2. V = pr2h 
3. V = Bh 

Joint variation means that V will be dependent on at least two different variables. Looking at the three choices, only 2 and 3 show this. 

In 2, V varies jointly as r2 and h (assuming p is the constant of proportionality). And in 3, V varies jointly as B and h, with the proportionality constant being 1.