Name: _____________________________________________ Date: _________ Hour:______
Direct Variation WS
Find the missing value in the direct variation.
1. If y varies directly with x, and y = 8 when x = 4, find x when y = 12.
2. If y varies directly with x, and y = 39 when x = 3, find y when x = 11.
3. If y varies directly with x, and y = 15 when x = 9, find y when x = -3.
4. If y varies directly with x, and y = 1.2 when x = 5, find x when y = 25.
Solve the direct variation
5. The number of gallons g of fuel used on a trip varies directly with the number of miles m traveled. If
a trip of 270 miles required 12 gallons of fuel, how many gallons are required for a trip of 400 miles?
6. Karen earns $28.50 for working six hours. If the amount m she earns varies directly with h the
number of hours she works, how much will she earn for working 10 hours?
7. A bottle of 150 vitamins costs $5.25. If the cost varies directly with the number of vitamins in the
bottle, what should a bottle with 250 vitamins cost?
8. The weight of an object on Mars varies directly with its weight on Earth. An object that weighs 70
pounds on Mars weighs 210 pounds on Earth. If an object weighs 160 pounds on Earth, how much
would it weigh on Mars?
9. The height of a wide-screen television screen is directly proportional to its width. A manufacturer
makes a television screen that is 60 centimeters wide and 33.75 centimeters high. Find the height of a
television screen that is 90 centimeters wide.
10. The diameter of a spider’s web varies directly with the number of hours the spider took to spin the
web. If a spider could spin a web with a 5 cm diameter in 3 hours, then how big of a diameter could
the spider spin if he spent 24 hours spinning a web?
11. The amount of time a child can pay attention varies directly with their age. If a 3 year old kid can
pay attention to something for 15 minutes, then how long can a 15 year old kid pay attention?
12. Determine which of the following graphs represent direct variations?
13. Which of the following equations are direct variation equations?
a) y = 5x – 2
b) y = ½ x
c) y = 5(3x + 15) – 75
d) y = 2x + 5
e) y = x
f) y = 2