Year 8
Year 8

The constant of proportionality

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Lesson details

Key learning points

  1. In this lesson, we will learn about the the term 'constant of proportionality' and how it relates to how proportion works.

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5 Questions

Q1.
Which graph does not show to direct proportion?
An image in a quiz
A
B
Correct answer: C
Q2.
Which graph shows direct proportion?
An image in a quiz
Correct answer: A
B
C
Q3.
Which table does not shows direct proportion?
An image in a quiz
A
B
Correct answer: C
Q4.
Which table does not shows direct proportion?
An image in a quiz
Correct answer: A
B
C
Q5.
x and y are directly proportional as shown in the graph. What is the value of y when x = 10?
An image in a quiz
20
22
Correct answer: 25

8 Questions

Q1.
Complete the sentence: When two quantities are in ........................ , when one variable doubles, the other doubles too.
constant of proportionality
Correct answer: direct proportion
indirect proportion
Q2.
Complete the sentence: When two quantities are in direction proportion, when one variable is zero, the other is .............
Correct answer: 0
10
2
Q3.
x and y are in direction proportion. When x is 4 y is 11. What is the value of y when x = 12?
23
Correct answer: 33
5
Q4.
The cost of T shirts online at £12 each. The postage charge is £3.50 per order. How much will it cost to order 2 T shirts?
£24
Correct answer: £27.50
£31
Q5.
Think about the previous question: Are the number of T-shirts and the cost in direct proportion?
Correct answer: No
Yes
Q6.
Which table shows direct proportion?
Correct answer: Option 1
Option 2
Option 3
Q7.
What is the constant of proportionality in the table below?
An image in a quiz
10
2
Correct answer: 5
Q8.
What is the constant of proportionality between m and n?
An image in a quiz
Correct answer: 2.5
4
5