Average
MCQs Math


Question:     What is the average of the first 1723 even numbers?


Correct Answer  1724

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 1723 even numbers are

2, 4, 6, 8, . . . . 1723 th terms

Calculation of the sum of the first 1723 even numbers

We can find the sum of the first 1723 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 1723 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 1723 even number,

n = 1723, a = 2, and d = 2

Thus, sum of the first 1723 even numbers

S1723 = 1723/2 [2 × 2 + (1723 – 1) 2]

= 1723/2 [4 + 1722 × 2]

= 1723/2 [4 + 3444]

= 1723/2 × 3448

= 1723/2 × 3448 1724

= 1723 × 1724 = 2970452

⇒ The sum of the first 1723 even numbers (S1723) = 2970452

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 1723 even numbers

= 17232 + 1723

= 2968729 + 1723 = 2970452

⇒ The sum of the first 1723 even numbers = 2970452

Calculation of the Average of the first 1723 even numbers

Formula to find the Average

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

Thus, The average of the first 1723 even numbers

= Sum of the first 1723 even numbers/1723

= 2970452/1723 = 1724

Thus, the average of the first 1723 even numbers = 1724 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 1723 even numbers = 1723 + 1 = 1724

Thus, the average of the first 1723 even numbers = 1724 Answer


Similar Questions

(1) Find the average of the first 2805 even numbers.

(2) Find the average of the first 4421 even numbers.

(3) Find the average of even numbers from 12 to 1562

(4) Find the average of the first 3769 odd numbers.

(5) Find the average of even numbers from 12 to 1754

(6) Find the average of the first 2427 even numbers.

(7) What is the average of the first 54 even numbers?

(8) Find the average of odd numbers from 9 to 423

(9) Find the average of odd numbers from 3 to 261

(10) Find the average of odd numbers from 5 to 1005


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©