When two quantities x and y are in _______ proportion or vary ______ they are written as x ∝ y

Solution:

The table below reveals the direct relation between variables x and y.

As evident from the above table as the value of x is increasing the value of y is also increasing.

Hence

x and y are in direct proportion or vary directly with each other.

When x and y are in direct proportion

x/y = constant = k

In the above table

x/y = k = 20

✦ Try This: Find the value of x/y from the table given below and state the relation between the two variables x and y.

Let us investigate the relationship x/y by using all the table values of x and y

x/y = 1/3 = 2/6 = 3/9 = 4/12 = 5/15 = 1/3 = k

Since k is a constant we can state that there exists a relationship between variable x and y which is of direct proportion. In other words x and y vary directly

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 13

NCERT Exemplar Class 8 Maths Chapter 10 Problem 19

When two quantities x and y are in _______ proportion or vary ______ they are written as x ∝ y

Summary:

When two quantities x and y are in direct proportion or vary directly they are written as x ∝ y

☛ Related Questions:

• When two quantities x and y are in ______ proportion or vary ______ they are written as x ∝ 1/y
• Both x and y are said to vary ______ with each other if for some positive number k, xy = k
• x and y are said to vary directly with each other if for some positive number k, ______ = k