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MCQs Math


Question:     Find the average of odd numbers from 5 to 607


Correct Answer  306

Solution And Explanation

Solution

Method (1) to find the average of the odd numbers from 5 to 607

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

The odd numbers from 5 to 607 are

5, 7, 9, . . . . 607

After observing the above list of the odd numbers from 5 to 607 we find that the difference between two consecutive terms are equal. This means the list of the odd numbers from 5 to 607 form an Arithmetic Series.

In the Arithmetic Series of the odd numbers from 5 to 607

The First Term (a) = 5

The Common Difference (d) = 2

And the last term (ℓ) = 607

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 odd numbers from 5 to 607

= 5 + 607/2

= 612/2 = 306

Thus, the average of the odd numbers from 5 to 607 = 306 Answer

Method (2) to find the average of the odd numbers from 5 to 607

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

The odd numbers from 5 to 607 are

5, 7, 9, . . . . 607

The odd numbers from 5 to 607 form an Arithmetic Series in which

The First Term (a) = 5

The Common Difference (d) = 2

And the last term (ℓ) = 607

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 odd numbers from 5 to 607

607 = 5 + (n – 1) × 2

⇒ 607 = 5 + 2 n – 2

⇒ 607 = 5 – 2 + 2 n

⇒ 607 = 3 + 2 n

After transposing 3 to LHS

⇒ 607 – 3 = 2 n

⇒ 604 = 2 n

After rearranging the above expression

⇒ 2 n = 604

After transposing 2 to RHS

⇒ n = 604/2

⇒ n = 302

Thus, the number of terms of odd numbers from 5 to 607 = 302

This means 607 is the 302th term.

Finding the sum of the given odd numbers from 5 to 607

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 odd numbers from 5 to 607

= 302/2 (5 + 607)

= 302/2 × 612

= 302 × 612/2

= 184824/2 = 92412

Thus, the sum of all terms of the given odd numbers from 5 to 607 = 92412

And, the total number of terms = 302

Since, the average of the given numbers

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

Thus, the average of the given odd numbers from 5 to 607

= 92412/302 = 306

Thus, the average of the given odd numbers from 5 to 607 = 306 Answer


Similar Questions

(1) Find the average of odd numbers from 5 to 99

(2) Find the average of even numbers from 4 to 40

(3) Find the average of even numbers from 6 to 1390

(4) Find the average of odd numbers from 5 to 889

(5) Find the average of the first 880 odd numbers.

(6) Find the average of odd numbers from 15 to 1613

(7) Find the average of even numbers from 4 to 1162

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(10) Find the average of the first 3030 odd numbers.


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