Recognizing Direct Variation in Tables and Equations

Eduardo counted ten seconds between seeing lightning and hearing thunder, and he knew that the lightning was about 2 miles away. What is the constant of variation?

• k = 10
• k = 2
• k = 5
• k = 1/5

A person’s weekly pay is directly proportional to the number of hours worked. Shawn’s pay is $123.00 for 20 hours of work. What is the constant of variation?

• k = 123
• k = 20
• k = 6.15
• k = 0.16

A person’s weekly pay is directly proportional to the number of hours worked. Shawn’s pay is $123.00 for 20 hours of work. Find the amount of pay for 31 hours of work. 

• $3813
• $620
• $190.65
• $4.96

At top speed, a rabbit can cover 7 miles in 12 minutes. What is the constant of variation?

• k = 7
• k = 12
• k = 12/7
• k = 7/12

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

A dishwasher uses 65 gallons of water to wash 5 loads of dishes. What is the constant of variation?

• k = 13
• k = 65
• k = 5
• k = 1/13

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

• Yes; 1/4
• Yes; 4
• Yes; 2
• No

Which of the given graphs is a direct variation?

• A
• B
• C
• D

Is this proportional?

• yes
• no

Write an equation for this relationship.

• y=4x
• y=1/8x
• y=1/4x
• y=8x