Inverse and Direct Variation

Is the given table a direct or inverse variation? What is the constant of variation?

• Direct, 12

• Inverse, 12

• Direct, 1/12

• Inverse, 1/12

Y varies directly with x, and y is 84 when x is 16. Which equation represents this situation?

• y=1344x

• y=100x

• y=5.25x

• y=4/21x

Is the given table a direct variation? If so, what is the constant of variation?

• Yes; 1/3

• Yes; 3

• Yes; 5

• No

The image is an example of the graph of a(n)

• direct variation

• inverse variation

• neither

• both

Y varies inversely with x, and y is 0.5 when x is 4. Which equation represents this situation?

• y=2x

• y=2/x

• y=4x

• y=x/2

If x and y are in an inverse variation then which of the following is correct?

• x - y = constant

• x + y = constant

• xy = constant 

• x⁄y is constant 

Given (32, 15) and (12, y). Find the constant k of inverse variation, and then find the missing y value.

• 40

• 48

• -40

• -48

The number of hours to paint a house varies inversely with the number of painters working. A 2400-square foot house can be painted in 27 hours by 6 painters. How many painters would need to work in order to paint the house in 18 hours?

• 8 painters

• 10 painters

• 9 painters

• 11 painters

The time it takes to fly from Los Angeles to New York varies inversely as the speed of the plane. If the trip takes 6 hours at 900 km/h, how long would it take at 800 km/h?

• 5.33 hours 

• 6.75 hours 

• 12 hours 

• 10 hours 

The gas pressure in a chamber varies directly with the temperature in the chamber. If the pressure in the chamber is 150 atmospheres (atm) when the chamber is at 50 degrees, what is the pressure in the chamber when the temperature of the chamber is 75 degrees?

• 175 atm

• 200 atm

• 225 atm

• 275 atm