Direct Variation

If y = 15 when x = 12 find y when x = 32.

• y = (5/4)x; 40

• y= (4/5)x; -40

• y= 4x; 5

• y= 5x; -5

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

• y = 10x

• y = 2x

• y = 5x

• y = 1/5x

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 this proportional?
y=2x

• yes

• no

A map of Texas is scaled so that 3 inches represents 90 miles. How far apart are Pecos and Fort Stockton if they are 1.8 inches apart on the map?

• 54 miles

• 15 miles

• 30 miles

• 50 miles

The value of y is directly proportional to the value of x.

If y = 132 when x = 11, what is the value of y when x = 17?

• y = 144

• y = 12

• y = 204

• y = 71

Does the following table represent direct variation?

• Yes

• No

Does the following table represent direct variation?

• Yes

• No

The number of pages that Hayden can read varies directly with the time spent reading. If he reads 12 pages in 4 minutes, how many pages can he read in 17 minutes?

• 51 pages

• 47 pages

• 60 pages

• 75 pages

The number of miles Jim runs is directly proportional to the time spent running.

If he runs 6 miles in 46.8 minutes, how long will it take him to run 13.1 miles?

• 92.35 minutes

• 7.8 minutes

• 102.18 minutes

• 150.67 minutes