Average
MCQs Math


Question:     Find the average of the first 4509 even numbers.


Correct Answer  4510

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 the given numbers

The first 4509 even numbers are

2, 4, 6, 8, . . . . 4509 th terms

Calculation of the sum of the first 4509 even numbers

We can find the sum of the first 4509 even 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 4509 even 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 the first 4509 even number,

n = 4509, a = 2, and d = 2

Thus, sum of the first 4509 even numbers

S4509 = 4509/2 [2 × 2 + (4509 – 1) 2]

= 4509/2 [4 + 4508 × 2]

= 4509/2 [4 + 9016]

= 4509/2 × 9020

= 4509/2 × 9020 4510

= 4509 × 4510 = 20335590

⇒ The sum of the first 4509 even numbers (S4509) = 20335590

Shortcut Method to find the sum of the first n even numbers

Thus, the sum of the first n even numbers = n2 + n

Thus, the sum of the first 4509 even numbers

= 45092 + 4509

= 20331081 + 4509 = 20335590

⇒ The sum of the first 4509 even numbers = 20335590

Calculation of the Average of the first 4509 even numbers

Formula to find the Average

Average = Sum of the given numbers/Number of the numbers

Thus, The average of the first 4509 even numbers

= Sum of the first 4509 even numbers/4509

= 20335590/4509 = 4510

Thus, the average of the first 4509 even numbers = 4510 Answer

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

(1) The average of the first 2 even numbers

= 2 + 4/2

= 6/2 = 3

Thus, the average of the first 2 even numbers = 3

(2) The average of the first 3 even numbers

= 2 + 4 + 6/3

= 12/3 = 4

Thus, the average of the first 3 even numbers = 4

(3) The average of the first 4 even numbers

= 2 + 4 + 6 + 8/4

= 20/4 = 5

Thus, the average of the first 4 even numbers = 5

(4) The average of the first 5 even numbers

= 2 + 4 + 6 + 8 + 10/5

= 30/5 = 6

Thus, the average of the first 5 even numbers = 6

Thus, the Average of the First n even numbers = n + 1

Thus, the average of the first 4509 even numbers = 4509 + 1 = 4510

Thus, the average of the first 4509 even numbers = 4510 Answer


Similar Questions

(1) What is the average of the first 1402 even numbers?

(2) What is the average of the first 1762 even numbers?

(3) Find the average of even numbers from 10 to 270

(4) Find the average of odd numbers from 13 to 1479

(5) Find the average of even numbers from 10 to 1204

(6) Find the average of even numbers from 8 to 646

(7) Find the average of the first 1470 odd numbers.

(8) Find the average of odd numbers from 5 to 131

(9) Find the average of the first 1121 odd numbers.

(10) Find the average of the first 3828 odd numbers.


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