Variation Problems

If y is directly proportional to x and y=15 when x=12, what is the value of y when x=16?

• 12.8
• 13.0
• 16.4
• 20.0

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 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

If y is directly proportional to x and x=5 when y=20, what is the constant of variation?

• 4
• 100
• 0.25
• 25

If x varies inversely as the square root of y, and x = 9 when y = 121, find x when y = 81.

• 7

• 11

• 13

• 17