A ratio gives the relationship between two or more values (or) shows the relative size of two or more numbers.

Comparing two quantities of the same units is called a ratio.
A ratio of two quantities can be expressed as a fraction also. For example, the ratio 3:4 can be expressed as $\frac{3}{4}$ and vice versa.

If two given ratios are the same, they are said to be in proportion.

The magnitude of quantities relative to each other is called the ratio of two quantities. It is usually expressed as “p to q” or “p : q”.

Examples on Ratios


Given below are some examples on ratios.

Example 1:

If a class of 40 students has 25 boys, then calculate the ratio of boys to girls?

Solution:

Total number of students in the class = 40
The number of boys in the class = 25
The number of girls in the class = 40 – 25 = 15
So, the ratio of ratio of boys to girls = 25 : 15

    = 5 : 3

Example 2:

If Kelly runs a mile in 6 minutes 50 seconds and jimmy takes 7 minutes 50 seconds, then calculate the ratio of kelly's time to Jimmy's time?

Solution:

6 minutes 50 seconds = (6 x 60) + 50

    = 360 + 50
    = 410 seconds.

7 minutes 50 seconds = (7 x 60) + 50
    = 420 + 50
    =470 seconds.

Ratio of Kelly's time to Jimmy's time = 410 : 470
    = 41 : 47