Identify Inverse Variation

Assume y varies inversely with x. If x=7 when y=4, what is y when x=2 ?

• 4
• 14 
• 7
• 28

What is the constant (k) in this inverse variation?
y = 400/x

• x
• y
• 400
• Not enough information given

Which of the following represents indirect variation?

• y = kx
• y = k/x
• y = x/k
• y = mx + b

If y varies inversely as x and x=5 when y=20, then what is the constant of variation, k? 

• 121
• 4
• 100
• 6

When Darcy's school bus travels at 30 miles per hour, it gets from her home to school in 12 minutes. What is the speed of Darcy's bus if it makes the same trip in 18 minutes?  

• 45 mph
• 36 mph
• 28 mph
• 20 mph

The cost per person to rent a mountain cabin is inversely proportional (varies inversely) to the number of people who share the rent. If the cost is $36 per person when 5 people share, what is the cost per person when 8 people share?

• $22.50
• $57.60
• $1.11
• $12.50

The current in an electrical conductor varies inversely as the resistance of the conductor. What is the current when the resistance is 42 ohms, if the current is 4 amperes when the resistance is 168 ohms?

• 21 amperes
• 17 amperes
• 24 amperes
• 16 amperes

The cost of producing pencils varies directly with the number of pencils produced. If the cost of producing 6,000 pencils is $400, then what will be the cost of production for 10,000 pencils?

• $612
• $604
• $600
• $610

The time to complete a project varies inversely with the number of employees.
If 3 people can complete the project in 7 days, how long will it take 5 people?

• 12 days
• 4.2 days
• 6.2 days
• 10 days

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

• 300
• 75
• 1,875
• 12