Module B Review

The equation w = 8c represents:

• direct variation

• inverse variation

• joint variation

• none of these

The graph represents:

• direct variation

• inverse variation

• neither direct nor inverse variation

• direct variation
• inverse variation
• neither direct nor inverse variation

• direct variation
• inverse variation
• neither direct nor inverse variation

The equation 
xy =  25  represents:

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

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

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

• Yes; 1/3
• Yes; 3
• Yes; 5
• No

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

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