Grade 9 - Quiz #3 Joint and Combined 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

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.REI.B.3

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

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.REI.B.3

CCSS.HSA.CED.A.2

CCSS.HSA.REI.A.1

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

• 300
• 75
• 1,875
• 12

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.CED.A.4

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.2

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

Tags

CCSS.HSA.CED.A.1

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

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

Tags

CCSS.7.RP.A.3

The number of minutes needed to solve an exercise set of variation problems varies directly as the number of problems and inversely as the number of people working on the solutions. It takes 4 people 36 minutes to solve 18 problems. How many minutes will it take 6 people to solve 42 problems.

• 56 minutes

• 52 minutes

• 48 minutes

• 44 minutes

Tags

CCSS.7.EE.B.3

The time it takes you to complete a puzzle is directly proportional to the number of pieces and inversely proportional to how many people are working on it. You and your three friends can complete a 1,000 piece puzzle in 2 hours. How long would it take you to complete a 2,500 piece puzzle?

• 8 hours

• 9 hours

• 10 hours

• 11 hours

Tags

CCSS.7.EE.B.3

The weight of a liquid varies directly as its volume V. If the weight of the liquid in a cubical container 5 cm on a side is 250 g, find the weight of the liquid in a cubical container 3 cm on a side.

• 12 g

• 6 g

• 27 g

• 54 g

Tags

CCSS.7.EE.B.4

CCSS.7.G.B.6

CCSS.7.RP.A.2

The distance it takes to stop a car varies directly as the square of the speed of the car. If it takes 112 feet for a car traveling at 40 miles per hour to stop, what distance is required for a speed of 65 miles per hour?

• 308.05 ft

• 295.75 ft

• 296.09 ft

• 253.5 ft

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.REI.B.4