

1. 
If y varies directly as the cube of x and y = 30 when x = 2, find x when y = 468.75. 


A. 
7 
B. 
5 


C. 
3 
D. 
9 


Hint 


2. 
If y varies inversely as x and y = 12 when x = 7, find x when y = 2. 


A. 
7 
B. 
5 


C. 
42 
D. 
10 


Hint 


3. 
If y varies inversely as the cube of x and y = 8 when x = 2, find x when y = 1. 


A. 
x = 8 
B. 
x = 4 


C. 
x = 1 
D. 
x = 2 


Hint 


4. 
If y varies jointly as x and the cube root of z, and y = 30 when x = 5 and z = 27, find y when z = 8 and x = 0.5. 


A. 
y = 2 
B. 
y = 4 


C. 
y = 2 
D. 
y = 20 


Hint 


5. 
Which best describes this graph? 





A. 
none of these 
B. 
joint variation 


C. 
direct variation 
D. 
inverse variation 


Hint 

