Constant of Variation and Direct Variation

Solve for the unknown variable:

If a varies directly as b and a = 12 when b = 20, what is the value of b if a = 123? (no space)

If z varies directly as r and z = 243 when r = 27. What is the value of z when r = 780? (do not use comma)

The distance covered by a moving object with a constant rate varies directly as the time it travelled. Milo walked 40 meters in 15 seconds. How long will it take him to walk 128 meters with a constant rate? (use small letter for the unit of measure, __ seconds)

Does this table of values represent a direct variation?

• Yes

• No

Does this represent a direct variation?

• Yes

• No

What is the constant of variation, k (in miles per hour) based on the table?

• 45

• 90

• 135

• 2

In a direct variation, y = 39 when x = 3. 
Find the value of y when x = 2.

• 26

• 3

• 58.5

• 2

The amount of money earned on a job varies directly 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

Which of the given graphs is a direct variation?

• A

• B

• C

• D

Write the direct variation equation for the table given.

• y = 1/3x

• y = 3x

• y = 1/2x