Summative Test - Variation and Radicals

The cost c varies directly as the number n of pencils is written as

• c = kn

• k = cn

The speed r of a moving object is inversely proportional to the time t travelled is written as

• r = kt

• t = kr

Which is an example of a direct variation?

• xy = 10

• y = 5x

A car travels a distance of d km in t hours. The formula that relates d to t is d = kt. What

kind of variation is it?

• direct

• inverse

• joint

• combined

y varies directly as x and y = 32 when x = 4. Find the constant of variation.

Which of the following describes an inverse variation?

• 
• 
• 
• 

What happens to T when h is doubled in the equation T = 4h?

• T is halved

• T is tripled

• T is doubled

• T becomes zero

If y varies directly as x and y = 12 when x = 4, find y when x = 12

What mathematical statement describes the graph below?

• lw = 36

• y is tripled

• y is doubled

• y is halved

• y is divided by 3