Direct Inverse and Joint

A is in joint variation with B and square of C. When A = 144, B = 4 and C = 3. Then what is the value of A when B = 6 and C = 4?

• 12

• 36

• 384

• 96

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

If y varies jointly with the product of x and z, and y = 1000 when x = 10 and z = 20, find y when x = 8 and z = 10.

• 100

• 300

• 200

• 400

Write the mathematical equation of the given statement: (no spacing, use / for fraction bar)

The time (t) needed to answer a set of problems is directly proportional to the number (N) of problems, and inversely proportional to the number of students (P) working on the solutions.

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

The cost C of fish varies directly as its weight w in kilogram.

• C =kw

• K= Cw

• W=kc

• K =w/c

if y varies directly as x, and y=30 and x=5. What is the constant of the variation?

• 3

• 9

• 6

• 12

which of the following statements illustrate a direct variation?

• z=knd

• c=k/d

• a=kb

• f=abc