Combined Variation

If y varies directly with x and inversely with z, and y = 24 when x = 48 and z = 4, find x when y = 44 and z = 6.

• 126

• 132

• 148

• 154

If f varies directly with g and inversely with the square of h, and f = 20 when g = 50 and h = 5, find f when g = 18 and h = 6.

• 4

• 5

• 8

• 10

If y varies jointly with a and b and inversely with the square root of c, and y = 12 when a = 3, b = 2, and c = 64, find y when a = 5, b = 2, and c = 25.

• 8

• 16

• 24

• 32

If x varies directly with y and inversely with z, and x = 10 when y = 5 and z = 3, for what value of z will x = 3 and y = 4?

• 2

• 4

• 6

• 8

The number of minutes needed to solve an exercise set of variation problems varies directly with the number of problems and inversely with the number of people working on the solutions. It takes 4 people 36 minutes to solve 18 problems. How many minutes will it take 6 people to solve 42 problems.

• 56 minutes

• 52 minutes

• 48 minutes

• 44 minutes

The time it takes you to complete a puzzle is directly proportional to the number of pieces and inversely proportional to how many people are working on it. You and your three friends can complete a 1,000 piece puzzle in 2 hours. How long would it take you to complete a 2,500 piece puzzle?

• 8 hours

• 9 hours

• 10 hours

• 11 hours