Variation

On a treasure map, the actual distance is directly related to the scaled distance.  If 15 miles is represented by 3 centimeters, then how many centimeters on the treasure map are equivalent to 135 miles?

• 27 cm
• 675 cm
• 529 cm
• 32 cm

The amount of money earned on a job is directly proportional to the number of hours worked.  If $70.00 is earned in 5 hours, how much money is earned in 22 hours of work?

• $2
• $308
• $1.57
• $265

At top speed, a rabbit can cover 7 miles in 12 minutes. If a rabbit could continue at this rate indefinitely, how long would it take the rabbit to cross the 220-mile expanse of the Mojave Desert? 

• 31.4 minutes
• 18.3 minutes
• 377.1 minutes
• 128.1 minutes

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

• 121
• 4
• 100
• 6

a varies inversely as the square of b. If a is 1 when b is 3, find a when b is 5. 

• 0.36
• 9
• 25
• 36

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 time to prepare a field for planting is inversely proportional to number of people who are working.
 A large field can be prepared by five workers in 24 days. In order to finish the field sooner, the farmer plans to hire additional workers.
How many workers are needed to finish the field in 15 days?

• 6  workers
• 10  workers
• 8  workers
• 4  workers

What type of variation does this scenario represent?
The grade you earn in a class
and the number of assignments you complete
and the number of hours you study

• 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 jointly as x & z. 
If y = -180 when z = 15
and x = -3,
then find y when x = 7 and z = -5.

• -140
• 140
• -4
• 4