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MCQs Math


Question:     Find the average of odd numbers from 3 to 535


Correct Answer  269

Solution And Explanation

Solution

Method (1) to find the average of the odd numbers from 3 to 535

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

The odd numbers from 3 to 535 are

3, 5, 7, . . . . 535

After observing the above list of the odd numbers from 3 to 535 we find that the difference between two consecutive terms are equal. This means the list of the odd numbers from 3 to 535 form an Arithmetic Series.

In the Arithmetic Series of the odd numbers from 3 to 535

The First Term (a) = 3

The Common Difference (d) = 2

And the last term (ℓ) = 535

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 3 to 535

= 3 + 535/2

= 538/2 = 269

Thus, the average of the odd numbers from 3 to 535 = 269 Answer

Method (2) to find the average of the odd numbers from 3 to 535

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

The odd numbers from 3 to 535 are

3, 5, 7, . . . . 535

The odd numbers from 3 to 535 form an Arithmetic Series in which

The First Term (a) = 3

The Common Difference (d) = 2

And the last term (ℓ) = 535

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 3 to 535

535 = 3 + (n – 1) × 2

⇒ 535 = 3 + 2 n – 2

⇒ 535 = 3 – 2 + 2 n

⇒ 535 = 1 + 2 n

After transposing 1 to LHS

⇒ 535 – 1 = 2 n

⇒ 534 = 2 n

After rearranging the above expression

⇒ 2 n = 534

After transposing 2 to RHS

⇒ n = 534/2

⇒ n = 267

Thus, the number of terms of odd numbers from 3 to 535 = 267

This means 535 is the 267th term.

Finding the sum of the given odd numbers from 3 to 535

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 3 to 535

= 267/2 (3 + 535)

= 267/2 × 538

= 267 × 538/2

= 143646/2 = 71823

Thus, the sum of all terms of the given odd numbers from 3 to 535 = 71823

And, the total number of terms = 267

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 3 to 535

= 71823/267 = 269

Thus, the average of the given odd numbers from 3 to 535 = 269 Answer


Similar Questions

(1) Find the average of odd numbers from 15 to 477

(2) Find the average of the first 2181 odd numbers.

(3) Find the average of even numbers from 12 to 162

(4) What is the average of the first 726 even numbers?

(5) Find the average of the first 3046 odd numbers.

(6) Find the average of even numbers from 12 to 1154

(7) Find the average of odd numbers from 3 to 29

(8) Find the average of the first 2711 even numbers.

(9) Find the average of even numbers from 8 to 290

(10) What is the average of the first 1875 even numbers?


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