Directly and Inversely Proportional Relationships

What type of proportion does the table represent?

• Direct

• Inverse

• I dont' know

g is directly proportional to b

Given g=20 when b=4.

Find g when b=7

• 35

• 5

• 15

• 23

The amount of money earned on a job is directly proportional to the number of hours worked.  If $70.00 is earned in 5 hours, how much money is earned in 22 hours of work?

• $2
• $308
• $1.57
• $265

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

The number of hours to paint a house varies inversely with the number of painters working. A 2400-square foot house can be painted in 27 hours by 6 painters. How many painters would need to work in order to paint the house in 18 hours?

• 8 painters
• 10 painters
• 9 painters
• 11 painters

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

The width of a rectangle varies inversely with its length. if the width is 4 when the length is 18, find the width when the length is 8.

• 9
• 72
• 36
• 2

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

2.The amount of money spent at the gas station varies directly with the number of gallons purchased. When 9.5 gallons of gas were purchased the cost was $36.52. How much would 12 gallons of gas cost?

• Direct Variation

• Inverse Variation

1.The number of pencils sold varies directly as the cost. If 5 pencils cost $0.45, find the cost of 7 pencils.

• Direct Variation

• Inverse Variation