Direct and Inverse Proportional

What is the value of y when x = 3?

• 18

• 20

• 23

• 43

What is the value of y when x = 4?

• 6

• 7

• 9

• 10.67

The time (t days) required to build a house is inversely proportional to the number of builders (n), all working at the same rate.

If there are 6 builders, it takes 80 days to complete the house.

How many builders must be employed to build the house in just 16 days?

• 1.2 builders

• 25 builders

• 30 builders

• 36 builders

R is inversely proportional to I.

Which of the following could be the graph connecting I and R?

• 
• 
• 
• 

The amount of sales tax on a new car is directly proportional to the purchase price of the car. Victor bought a new car for $30,000 and paid $1,500 in sales tax. Wesley bought a new car from the same dealer and paid $2,375 sales tax. How much did Wesley pay for his car?

• $18,947

• $30,875

• $45,000

• $47,500

The cost of insurance on a house is directly proportional to the area of the house.

Alan has a 2,500 square-foot house and pays a monthly insurance premium of $67.50

Bella has a 3,800 square-foot house insured with the same company. What is her monthly premium?

• $44.41

• $80.50

• $102.60

• $120.60

The acceleration of a particle is inversely proportional to the square of the time since it was fired.

If the acceleration of the particle 20 seconds after it was fired was 5 m/sec², what was its acceleration 5 seconds later?

• 3.2 m/s^2

• 4 m/s^2

• 6.4 m/s^2

• 20 m/s^2

John and Karen both insure their properties with the Budget Insurance Company. The cost of house insurance premiums with the Budget Insurance Company is directly proportional to the value of the property being insured. John pays premiums of $76 per month on his property valued at $152,000 How much does Karen pay on her property valued at $259,000?

• $44.60

• $129.50

• $183.00

• $205.50

Solve the proportion.

• k=5

• k=3.3333333

• k=60

• k=90

Solve for x 

• x = 1/10

• x = 10

• x = 4

• x = 5