SSLG REVIEWER: MATHEMATICS 9

If y varies jointly as x and z, and y = 12 when x = 2 and z = 3, find y when x = 4 and z = 6.

• 24

• 48

• 72

• 96

If z varies directly as x and inversely as y, and z = 6 when x = 3 and y = 2, find z when x = 4 and y = 3.

• 4

• 8

• 12

• 16

The area of a triangle varies jointly with its base and height. If a triangle with a base of 6 cm and a height of 8 cm has an area of 24 cm², what is the area of a triangle with a base of 10 cm and a height of 12 cm?

• 30 cm²

• 60 cm²

• 120 cm²

• 240 cm²

If w varies directly as x and inversely as the square of y, and w = 18 when x = 6 and y = 1, find w when x = 3 and y = 2.

• 1.5

• 3

• 6

• 9/2

The volume of a sphere varies directly as the cube of its radius. If a sphere with a radius of 2 cm has a volume of (32/3)π cm³, what is the volume of a sphere with a radius of 4 cm?

• (64/3)π cm³

• (128/3)π cm³

• (256/3)π cm³

• (512/3)π cm³

If p varies jointly as q and r, and p = 20 when q = 5 and r = 2, find k, the constant of variation.

• 2

• 4

• 5

• 10

If a varies inversely as b, and a = 10 when b = 5, find a when b = 2.

• 25

• 50

• 100

• 20

The intensity of sound varies inversely with the square of the distance from the source. If the intensity is 10 units at 1 meter, what is the intensity at 2 meters?

• 2.5 units

• 5 units

• 20 units

• 40 units

If y varies directly as the square of x and inversely as z, and y = 12 when x = 2 and z = 3, find y when x = 4 and z = 6.

• 16

• 24

• 32

• 48

The force of gravity between two objects varies inversely as the square of the distance between them. If the force is 100 units when the distance is 1 unit, what is the force when the distance is 2 units?

• 25 units

• 50 units

• 200 units

• 400 units