Direct and Indirect Proportions

6 pipes fill a tank in 120 minutes, then 5 pipes can fill it in _______ minutes

• 100 

• 174

• 144

• 108

The population of a country and the area of land per person are inversely proportional

• TRUE

• FALSE

Solve the proportion:

• c=4

• c=8

• c=14

• c=10

If x and y are in an inverse variation then which of the following is correct?

• x - y = constant

• x + y = constant

• xy = constant 

• x⁄y is constant 

Y varies directly as x. If y = 12 when x = 15, what is y when x = 20?

• 4/5

• 17

• 16

• 25

Lisa can fold 48 paper stars in 2 hours.

How many stars can she fold in 3 h?

• 72

• 63

• 54

• 48

You spend $40 on 5 pounds of concrete. What is the unit rate in dollars per pound?

• $8 per pound

• $5 per pound

• $35 per pound

• 0.125 pounds per dollar

n varies directly with c. If c = 24 when n = 18, what is c when n = 22?

• 88/3

• 28

• 66/4

• 24

Which equation exhibits a direct proportion?

• y = 5x - 2

• y = 3/4 x

• y - x = 4

• x = 6