Review Direct, Inverse and Joint Variation

• direct variation
• inverse variation
• joint variation
• none of these

• direct variation
• inverse variation
• joint variation
• none of these

What type of variation does this scenario represent?
The outside temperature
and the number of layers of clothes you need to wear outside to feel comfortable 

• direct variation

• inverse variation

• joint variation

• none of these

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

• 300

• 75

• 1,875

• 12

What kind of variation does this equation show?
y = 6x

• Inverse Variation

• Direct Variation

• No Variation

• Joint Variation

The number of hours h to paint a particular house varies inversely with the number of painters p. This house can be painted in 27 hours by 6 painters.

Find the value of k and write the equation. How many painters would need to work in order to paint the house in 18 hours?

• 8 painters

• 10 painters

• 9 painters

• 11 painters

What type of variation does this scenario represent?

The length of time you charge your cell phone

and

the battery power on your phone

• direct variation

• inverse variation

• joint variation

• none of these

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

• y = 1344 x

• y = 100 x

• y = 5.25 x

• y = 4/21 x

Y varies directly with x, and y = 39 when x = 3. Figure out k and write the equation. Then find the value of y when x = 2.

• 26

• 3

• 58.5

• 2

Y varies inversely with x. Given that y = 20 when x = 5, what is the value of the constant k?

• 4

• 5

• 25

• 100