# 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.

x |
0.40 |
0.80 |
1.2 |
2 |
2.4 |

y |
0.02 |
0.04 |
0.06 |
0.1 |
6 |

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.

x |
1 |
2 |
3 |
4 |
5 |

y |
3 |
6 |
9 |
12 |
15 |

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:**

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