Joint Variation Word Problems

y varies jointly as x and z. If y = -40 when x = -2 and z = -1, what is the variation equation?

• y = -2xz

• y = -40xz

• y = 20xz

• y= -20xz

z varies jointly with x and y. If x = 2, y = 3 and z = 18, find z when x = -6 and y = 2.

• -36

• -10

• -24

• -12

z varies jointly with x and y. If x = 5, y = -1, and z = 10. Find z when x = -1 and y = 7.

• 14

• 7

• -21

• -7

Solve for the constant of variation, k. (Use / for the fraction bar)

z varies jointly as x and y. x=3, when y=-8 and z=6.

m varies jointly as n and p. If m=36 when n=3 and p=4, find n if m=96 and p=4.

Write the given statement in mathematical equation. (no spacing)

r varies jointly as s and w

Write the given statement in mathematical equation. (no spacing)

Interest (I) varies jointly as the principal (P) amount deposited, the rate (r) and time (t) of the deposit.

y varies jointly as x and z.

If y= -40 when x= -2 and z= -1, find y when x=4 and z= -3.

Kinetic energy Ke varies jointly as the mass m and the square of the velocity V. A mass of 7 grams and a velocity of 4cm/s has a kinetic energy of 80 ergs. Find the kinetic energy for a mass of 9 grams and a velocity of 5 cm/s. (Write your final answer in fraction and of the form __ ergs)

The price P of an aluminum tube is jointly proportional to its radius r and the length l. If a 12-foot pipe with 5-inch radius costs 5250 pesos, how much will be the cost of a 9-foot pipe with a 6-inch radius? (Write your final answer without comma in the form: __ pesos)