Direct, Inverse, Joint Variations

Suppose y varies directly as x, and y=39 when x=3.  Find the value of y when x=2.

• 26
• 3
• 58.5
• 2

Suppose y varies jointly as x & z. 
If y = -180 when z = 15
and x = -3,
then find y when x = 7 and z = -5.

• -140
• 140
• -4
• 4

Suppose y varies inversely with x.
If y = 150 when x = 2, find y when x = 25.

• 300
• 75
• 1,875
• 12

Suppose p varies directly as r, and p varies inversely as t.
t = 20 when p = 4 and r = 2.
Find t when r = 10 and p = -5.

• 80
• -80
• 4
• -20

Suppose y varies directly as x.
If  y = 22.5 when x = 15, find y when x = 20.

• 1.5
• 337.5
• 30
• 16.875

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

Suppose j varies inversely with m.
If j = 60 when m = 0.3 , find j when m = -2

• -9
• 9
• 400
• -400

Suppose f varies directly as g, and f varies inversely as h.
f = -12 when h = 4 and g = -3.
Find g when f = 28 and h = 8.

• 14
• -14
• 16
• -16