Combined and Joint Variation

If y varies directly as x and inversely as 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 as g and inversely as 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 as a and b and inversely as 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 as y and inversely as 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

z varies inversely with x and directly with y. If x = 4, y = 48 and z = -2, find x when z = 8 and y = 96.

• -2

• -1

• 0

• 1

z varies inversely with x and directly with y. If x = 1/2, y = 5 and z = 20, find x when z = -4 and y = 8.

• 1

• 2

• 3

• 4

The formula for Combined Variation is represented as:

• y = kx

• y = k/x

• y = kxz

• y = kx/z

If p varies directly as the square of q and inversely as the square root of r, and p = 60 when q = 6 and r = 81, find p when q = 8 and r = 144.

• 70

• 80

• 90

• 100

Suppose a varies jointly as b & c. 
If a = 15 when b = 4
and c = 5,
then find b when a = 60 and c = 5.

• 320
• 225
• 16
• 8

z varies jointly with x and y. z = 12 when x = 8 and y = 6. Write a specific equation.

• x = 4zy

• x = 1/4 zy

• z = 4xy

• z = 1/4 xy