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MCQs Math


Question:     Find the average of even numbers from 6 to 1214


Correct Answer  610

Solution And Explanation

Solution

Method (1) to find the average of the even numbers from 6 to 1214

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

The even numbers from 6 to 1214 are

6, 8, 10, . . . . 1214

After observing the above list of the even numbers from 6 to 1214 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 6 to 1214 form an Arithmetic Series.

In the Arithmetic Series of the even numbers from 6 to 1214

The First Term (a) = 6

The Common Difference (d) = 2

And the last term (ℓ) = 1214

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 1214

= 6 + 1214/2

= 1220/2 = 610

Thus, the average of the even numbers from 6 to 1214 = 610 Answer

Method (2) to find the average of the even numbers from 6 to 1214

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

The even numbers from 6 to 1214 are

6, 8, 10, . . . . 1214

The even numbers from 6 to 1214 form an Arithmetic Series in which

The First Term (a) = 6

The Common Difference (d) = 2

And the last term (ℓ) = 1214

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 1214

1214 = 6 + (n – 1) × 2

⇒ 1214 = 6 + 2 n – 2

⇒ 1214 = 6 – 2 + 2 n

⇒ 1214 = 4 + 2 n

After transposing 4 to LHS

⇒ 1214 – 4 = 2 n

⇒ 1210 = 2 n

After rearranging the above expression

⇒ 2 n = 1210

After transposing 2 to RHS

⇒ n = 1210/2

⇒ n = 605

Thus, the number of terms of even numbers from 6 to 1214 = 605

This means 1214 is the 605th term.

Finding the sum of the given even numbers from 6 to 1214

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 1214

= 605/2 (6 + 1214)

= 605/2 × 1220

= 605 × 1220/2

= 738100/2 = 369050

Thus, the sum of all terms of the given even numbers from 6 to 1214 = 369050

And, the total number of terms = 605

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 1214

= 369050/605 = 610

Thus, the average of the given even numbers from 6 to 1214 = 610 Answer


Similar Questions

(1) Find the average of the first 3384 even numbers.

(2) Find the average of odd numbers from 5 to 665

(3) Find the average of even numbers from 10 to 162

(4) Find the average of the first 271 odd numbers.

(5) Find the average of even numbers from 4 to 414

(6) Find the average of the first 3672 odd numbers.

(7) Find the average of even numbers from 10 to 1456

(8) Find the average of odd numbers from 7 to 67

(9) Find the average of even numbers from 8 to 30

(10) Find the average of the first 1430 odd numbers.


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