Average
MCQs Math


Question:     What will be the average of the first 4378 odd numbers?


Correct Answer  4378

Solution And Explanation

Explanation

Method to find the average

Step : (1) Find the sum of given numbers

Step: (2) Divide the sum of given number by the number of numbers. This will give the average of given numbers

The first 4378 odd numbers are

1, 3, 5, 7, 9, . . . . 4378 th terms

Calculation of the sum of the first 4378 odd numbers

We can find the sum of the first 4378 odd numbers by simply adding them, but this is a bit difficult. And if the list is long, it is very difficult to find their sum. So, in such a situation, we will use a formula to find the sum of given numbers that form a particular pattern.

Here, the list of the first 4378 odd numbers forms an Arithmetic series

In an Arithmetic Series, the common difference is the same. This means the difference between two consecutive terms are same in an Arithmetic Series.

The sum of n terms of an Arithmetic Series

Sn = n/2 [2a + (n – 1) d]

Where, n = number of terms, a = first term, and d = common difference

In the series of first 4378 odd number,

n = 4378, a = 1, and d = 2

Thus, sum of the first 4378 odd numbers

S4378 = 4378/2 [2 × 1 + (4378 – 1) 2]

= 4378/2 [2 + 4377 × 2]

= 4378/2 [2 + 8754]

= 4378/2 × 8756

= 4378/2 × 8756 4378

= 4378 × 4378 = 19166884

⇒ The sum of first 4378 odd numbers (Sn) = 19166884

Shortcut Method to find the sum of first n odd numbers

Thus, the sum of first n odd numbers = n2

Thus, the sum of first 4378 odd numbers

= 43782 = 19166884

⇒ The sum of first 4378 odd numbers = 19166884

Calculation of the Average of the first 4378 odd numbers

Formula to find the Average

Average = Sum of given numbers/Number of numbers

Thus, The average of the first 4378 odd numbers

= Sum of first 4378 odd numbers/4378

= 19166884/4378 = 4378

Thus, the average of the first 4378 odd numbers = 4378 Answer

Shortcut Trick to find the Average of the first n odd numbers

The average of the first 2 odd numbers

= 1 + 3/2

= 4/2 = 2

Thus, the average of the first 2 odd numbers = 2

The average of the first 3 odd numbers

= 1 + 3 + 5/3

= 9/3 = 3

Thus, the average of the first 3 odd numbers = 3

The average of the first 4 odd numbers

= 1 + 3 + 5 + 7/4

= 16/4 = 4

Thus, the average of the first 4 odd numbers = 4

The average of the first 5 odd numbers

= 1 + 3 + 5 + 7 + 9/5

= 25/5 = 5

Thus, the average of the first 5 odd numbers = 5

Thus, the Average of the the First n odd numbers = n

Thus, the average of the first 4378 odd numbers = 4378

Thus, the average of the first 4378 odd numbers = 4378 Answer


Similar Questions

(1) Find the average of even numbers from 12 to 864

(2) Find the average of the first 3161 even numbers.

(3) Find the average of odd numbers from 15 to 983

(4) What will be the average of the first 4647 odd numbers?

(5) Find the average of even numbers from 4 to 1012

(6) Find the average of odd numbers from 3 to 215

(7) Find the average of odd numbers from 15 to 1791

(8) Find the average of the first 4086 even numbers.

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