Average
MCQs Math


Question:     Find the average of the first 2238 even numbers.


Correct Answer  2239

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 2238 even numbers are

2, 4, 6, 8, . . . . 2238 th terms

Calculation of the sum of the first 2238 even numbers

We can find the sum of the first 2238 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 2238 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 2238 even number,

n = 2238, a = 2, and d = 2

Thus, sum of the first 2238 even numbers

S2238 = 2238/2 [2 × 2 + (2238 – 1) 2]

= 2238/2 [4 + 2237 × 2]

= 2238/2 [4 + 4474]

= 2238/2 × 4478

= 2238/2 × 4478 2239

= 2238 × 2239 = 5010882

⇒ The sum of the first 2238 even numbers (S2238) = 5010882

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 2238 even numbers

= 22382 + 2238

= 5008644 + 2238 = 5010882

⇒ The sum of the first 2238 even numbers = 5010882

Calculation of the Average of the first 2238 even numbers

Formula to find the Average

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

Thus, The average of the first 2238 even numbers

= Sum of the first 2238 even numbers/2238

= 5010882/2238 = 2239

Thus, the average of the first 2238 even numbers = 2239 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 2238 even numbers = 2238 + 1 = 2239

Thus, the average of the first 2238 even numbers = 2239 Answer


Similar Questions

(1) Find the average of the first 555 odd numbers.

(2) Find the average of odd numbers from 9 to 615

(3) What will be the average of the first 4584 odd numbers?

(4) What will be the average of the first 4032 odd numbers?

(5) Find the average of even numbers from 6 to 1930

(6) Find the average of even numbers from 6 to 1104

(7) Find the average of odd numbers from 9 to 645

(8) Find the average of the first 2117 even numbers.

(9) What will be the average of the first 4313 odd numbers?

(10) What is the average of the first 1319 even numbers?


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