Real-Life Applications of Joint Variation in Action

A car's fuel consumption varies jointly with the distance traveled and the weight of the cargo. If a car uses 10 gallons of fuel to travel 200 miles with a cargo weight of 1,000 pounds, how much fuel will it use to travel 300 miles with a cargo weight of 1,500 pounds?

• 22.5 gallons

• 30 gallons

• 18 gallons

• 15 gallons

The area of a rectangle varies jointly with its length and width. If a rectangle with a length of 5 meters and a width of 3 meters has an area of 15 square meters, what will be the area of a rectangle with a length of 8 meters and a width of 4 meters?

• 32 square meters

• 24 square meters

• 40 square meters

• 20 square meters

The cost of producing a certain product varies jointly with the number of units produced and the cost per unit. If producing 100 units at $5 each costs $500, how much will it cost to produce 150 units at $6 each?

• $1200

• $750

• $600

• $900

The brightness of a light bulb varies jointly with the voltage and the current. If a bulb operates at 120 volts and 2 amps, producing a brightness of 240 lumens, how bright will it be at 150 volts and 3 amps?

• 120 lumens

• 450 lumens

• 600 lumens

• 300 lumens

The amount of paint needed to cover a wall varies jointly with the wall's height and width. If it takes 2 gallons to paint a wall that is 10 feet high and 12 feet wide, how many gallons are needed for a wall that is 15 feet high and 20 feet wide?

• 4 gallons

• 6 gallons

• 3 gallons

• 5 gallons

The speed of a boat varies jointly with the power of the engine and the weight of the boat. If a boat with a 100 HP engine and a weight of 1,500 pounds travels at 30 mph, what speed can be expected for a boat with a 150 HP engine and a weight of 2,000 pounds?

• 25 mph

• 40 mph

• 28 mph

• 33.75 mph

The volume of a gas varies jointly with its temperature and pressure. If a gas has a volume of 10 liters at 300 K and 2 atm, what will be the volume at 400 K and 3 atm?

• 20 liters

• 25 liters

• 5 liters

• 15 liters

The profit from selling a product varies jointly with the number of items sold and the price per item. If selling 50 items at $20 each yields a profit of $1,000, what profit can be expected from selling 75 items at $25 each?

• 1875

• 1500

• 2250

• 2000

The strength of a material varies jointly with its thickness and the type of material. If a material 2 cm thick has a strength of 200 N, what will be the strength of a 3 cm thick material of the same type?

• 150 N

• 250 N

• 400 N

• 300 N

The time it takes to complete a task varies jointly with the number of workers and the hours they work. If 4 workers can complete a task in 10 hours, how long will it take 6 workers to complete the same task?

• 12 hours

• 8 hours

• 15 hours

• 20 hours