Combined Variation

The formula for Combined Variation is represented as:

• y = kx

• y = k/x

• y = kxz

• y = kx/z

If s varies directly as t and inversely as v, then which of the following equations describes the relation among the three variables s, t, and v?

• s = k / tv

• s = kv / t

• 1/s = kt/ v

• s = kt / v

The cost c varies directly as the number of n pencils is written as

• c = kn

• k = cn

• n = k/c

• c = k/n

Solve for the constant of variation, k.

A varies directly as D and inversely as F. A=10.5, when D=2 and F=4

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

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

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