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MCQs Math


Question:     Find the average of even numbers from 6 to 506


Correct Answer  256

Solution And Explanation

Solution

Method (1) to find the average of the even numbers from 6 to 506

Shortcut Trick to find the average of the given continuous even numbers

The even numbers from 6 to 506 are

6, 8, 10, . . . . 506

After observing the above list of the even numbers from 6 to 506 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 6 to 506 form an Arithmetic Series.

In the Arithmetic Series of the even numbers from 6 to 506

The First Term (a) = 6

The Common Difference (d) = 2

And the last term (ℓ) = 506

The average of the numbers forming an Arithmetic Series

= The first term (a) + The last term (ℓ)/2

⇒ The average of numbers forming an Arithmetic Series = a + ℓ/2

Thus, the average of the even numbers from 6 to 506

= 6 + 506/2

= 512/2 = 256

Thus, the average of the even numbers from 6 to 506 = 256 Answer

Method (2) to find the average of the even numbers from 6 to 506

Finding the average of given continuous even numbers after finding their sum

The even numbers from 6 to 506 are

6, 8, 10, . . . . 506

The even numbers from 6 to 506 form an Arithmetic Series in which

The First Term (a) = 6

The Common Difference (d) = 2

And the last term (ℓ) = 506

The Average of the given numbers

= Sum of the given numbers/Total number of given numbers

Thus, to find the average of the given numbers, first, we need to find their sum and the total number of given numbers

Finding the number of terms

For an Arithmetic Series, the nth term

an = a + (n – 1) d

Where

a = First term

d = Common difference

n = number of terms

an = nth term

Thus, for the given series of the even numbers from 6 to 506

506 = 6 + (n – 1) × 2

⇒ 506 = 6 + 2 n – 2

⇒ 506 = 6 – 2 + 2 n

⇒ 506 = 4 + 2 n

After transposing 4 to LHS

⇒ 506 – 4 = 2 n

⇒ 502 = 2 n

After rearranging the above expression

⇒ 2 n = 502

After transposing 2 to RHS

⇒ n = 502/2

⇒ n = 251

Thus, the number of terms of even numbers from 6 to 506 = 251

This means 506 is the 251th term.

Finding the sum of the given even numbers from 6 to 506

The sum of all terms (S) in an Arithmetic Series

= n/2 (a + ℓ)

Where, n = number of terms

a = First term

And, ℓ = Last term

Thus, the sum of all terms (S) of the given even numbers from 6 to 506

= 251/2 (6 + 506)

= 251/2 × 512

= 251 × 512/2

= 128512/2 = 64256

Thus, the sum of all terms of the given even numbers from 6 to 506 = 64256

And, the total number of terms = 251

Since, the average of the given numbers

= Sum of the given numbers/Total number of given numbers

Thus, the average of the given even numbers from 6 to 506

= 64256/251 = 256

Thus, the average of the given even numbers from 6 to 506 = 256 Answer


Similar Questions

(1) Find the average of even numbers from 4 to 862

(2) Find the average of the first 4166 even numbers.

(3) Find the average of even numbers from 10 to 1388

(4) Find the average of the first 2166 even numbers.

(5) Find the average of odd numbers from 9 to 963

(6) Find the average of the first 1821 odd numbers.

(7) What is the average of the first 1802 even numbers?

(8) Find the average of the first 887 odd numbers.

(9) What is the average of the first 798 even numbers?

(10) Find the average of odd numbers from 15 to 825


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