Inverse Variation

Which of the following represents direct variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

Is this a direct variation?
y=2x

• yes

• no

What ordered pair does a direct variation always go through when graphed?

• (0, 0)

• (1, 0)

• (0, 1)

• (1, 1)

Which of the following represents inverse variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

The value of y varies directly with x.  Which function represents the relationship between x and y if y = 14 when x = 6. 

• y=20x

• y=84x

• y=7/3x

• y=3/7x

Given that y varies inversely with x, if x =7 and y = 4, what is y when x = 2?

• 14

• 10

• 2

• -14

Suppose y varies directly as x.
If  y = 22.5 when x = 15, find y when x = 20.

• 1.5

• 337.5

• 30

• 16.875

Suppose y varies inversely with x.
If y = 150 when x = 2, find y when x = 25.

• 300

• 75

• 1,875

• 12

The number of kilograms of water in a person’s body varies directly as the person’s mass.  A person with a mass of 90 kg contains 60 kg of water.  How many kilograms of water are in a person whose mass is 75 kg?

• 50 kg water

• 72 kg water

• 94 kg water

• 150 kg water

A person’s weekly pay is directly proportional to the number of hours worked. Shawn’s pay is $123.00 for 20 hours of work. What is the constant of variation?

• k = 123

• k = 20

• k = 6.15

• k = 0.16