Direct and inverse variation

Direct and inverse variation

Class VIII

Multiple Choice

1. If the cost of 20 books is ₹ 180, how much will 15 books cost?

• ₹150

• ₹135

• ₹130

• ₹120

Multiple Choice

Ounces of medication vary directly with the weight of the patient. If a 120-pound adult requires 3 ounces of a medication, then how many ounces would be needed for a 200-pound adult?

• 2

• 3

• 5

• 9

Multiple Choice

What type of variation does this scenario represent?
You and some friends decide to buy 2 pizzas and split the cost evenly.
The number of friends who are sharing the cost of the pizzas
and the amount of money you pay for your share.

• direct variation
• inverse variation
• joint variation
• none of these

Multiple Choice

What type of variation does this scenario represent?
The outside temperature
and the number of layers of clothes you need to wear outside to feel comfortable 

• direct variation
• inverse variation
• joint variation
• none of these

Multiple Choice

What type of variation does this scenario represent?
The length of time you charge your cell phone
and the battery power 

• direct variation
• inverse variation
• joint variation
• none of these

Multiple Choice

Is the given table a direct or inverse variation? What is the constant of variation?

• Direct. k = 12

• Inverse. k = 12

• Direct. k = 1/12

• Inverse. k = 1/12

Multiple Choice

Is the given table a direct variation? If so, what is the constant?

• Yes; 1/4

• Yes; 4

• Yes; 2

• No

Multiple Choice

Is the given table a direct variation? If so, what is the constant of variation?

• Yes; 1/3
• Yes; 3
• Yes; 5
• No

Multiple Choice

The number of kilograms of water in a person’s body varies directly as the person’s mass.  A person with a mass of 90 kg contains 60 kg of water.  How many kilograms of water are in a person whose mass is 75 kg?

• 50 kg water
• 72 kg water
• 94 kg water
• 150 kg water

Multiple Choice

The Height of a wave in California varies directly with the seconds that pass by.  At 4 seconds, the wave is 6 feet high.  How many seconds will give you a wave that is 10 feet high? 

• y = 2/3x
• 6
• 6.6
• 7

Multiple Choice

 Y varies directly with x, and y is 84 when x is 16. Which equation represents this situation?

• y=1344x
• y=100x
• y=5.25x
• y=4/21x

Multiple Choice

If x₁ = 5, y₁ = 7.5, x₂ = 7.5 then find y₂ if x and y vary directly.

• 11

• 11.5

• 11.25

• 11.75

Multiple Choice

If 3 kg of sugar contains 9 × 10⁸ crystals. How many sugar crystals are there in 4 kg of sugar?

• 1.2x 10⁹

• 1.2x10⁸

• 12x10⁹

• 1.2x10⁷

Multiple Choice

A boy runs 1 km in 10 minutes. How long will he take to run 600 m ?

• 2 min

• 3 min

• 4 min

• 6 min

Multiple Choice

What is the cost of 50 sticks at Rs 24 per score ?

• 30

• 40

• 50

• 60

Multiple Choice

If 3 quintals of coal cost ₹ 6000, what is the cost of 120 kg ?

• ₹1200

• ₹2400

• ₹3600

• ₹4800

Multiple Choice

If 20 cows eat as much as 15 oxen, how many cows will eat as much as 36 oxen ?

• 24

• 36

• 46

• 48

Multiple Choice

If 8 men can do a piece of work in 20 days, in how many days could 20 men do the same work ?

• 8

• 10

• 4

• 6

Multiple Choice

6 pipes are required to fill a tank in 1 hour. How long will it take if only 5 pipes of the same type are used ?

• 75 min

• 72 min

• 80 min

• 90 min

Multiple Choice

If 12 workers can build a wall in 50 hours, then how many more workers will be required to do the same work in 40 hours?

• 4

• 5

• 3

• 2