Question

In this series of numbers given; 5.2, 4.8, 4.4, 4.0, what is the next number?
A). 3
B). 3.3
C). 3.5
D). 3.6

Answer 1

Hint: Series of numbers can be defined as a list of numbers, arranged in a particular manner, each number separated by a comma. Every number has a relation with its consecutive number and so on. You can take an example of multiplication tables. Let us consider table 3.
3, 6, 9, 12, 15. When we subtract 3 from 6, we get 3, subtract 6 from 9, we get 3 and so on. This is a simple subtraction series.

Complete step-by-step solution:
Given: A series of numbers: 5.2, 4.8, 4.4, 4.0
To find: Next term of the series.
When we look at the given series, we can say that it is a decreasing order of numbers.
As the series is a decreasing series, we can look for the relation of common difference. Now, let’s find out whether the difference between the numbers given in the series is the same or not. If not, we need to find some different approach, by which we come to know about the relationship.
Difference between 1st and 2nd number:
$5.2 - 4.8 = 0.4\, \, \to \left (1 \right)$
Difference between 2nd and 3rd number:
$4.8 - 4.4 = 0.4\, \to \left (2 \right)$
Difference between 3rd and 4th number:
$4.4 - 4.0 = 0.4\, \to \left (3 \right)$
From equations 1, 2 and 3, we can say that there is a common difference of 0.4.
So, to find the next number of the series, we just have to subtract 0.4 from the last number of the series.
Subtracting 0.4 from 4.0,
$4.0 - 0.4 = 3.6$
Therefore, 3.6 becomes the next number of the series.
Hence, from the given multiple choices – the D option is the correct answer.

Note: Determining the relationship between a number and its consecutive number throughout the series has to be the important part of the answer. We cannot just find the relation between the first two numbers given in the series and declare the relation to be the same for the rest of the series. Relationship between the numbers throughout the series is in accordance but not similar.