Variations

If y varies directly with x and y = 6 when x = 2, what is y when x = 5?

• 1 15
• 2 12
• 3 10
• 4 30

If y is inversely proportional to x and y = 4 when x = 3, what is y when x = 6?

• 1 12
• 2 1
• 3 8
• 4 2

In y = k x, k is called:

• 1 Constant of variation
• 2 Slope only
• 3 Exponent
• 4 Variable

If a is proportional to b² and a = 8 when b = 2, what is a when b = 3?

• 1 27
• 2 18
• 3 24
• 4 12

Speed and time for a fixed distance are in:

• 1 Direct variation
• 2 Joint variation
• 3 Inverse variation
• 4 No variation

If y is proportional to x and y = 10 when x = 2, then k is:

• 1 12
• 2 20
• 3 8
• 4 5

If xy = 20 and x = 5, then y is:

• 1 100
• 2 4
• 3 15
• 4 25

If the speed is doubled and the distance is fixed, the time:

• 1 Is unchanged
• 2 Is four times
• 3 Is doubled
• 4 Is halved

The area of a circle varies directly with the square of its:

• 1 Diameter only
• 2 Circumference only
• 3 Colour
• 4 Radius