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MCQs Math


Question:     Find the average of even numbers from 6 to 2000


Correct Answer  1003

Solution And Explanation

Solution

Method (1) to find the average of the even numbers from 6 to 2000

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

The even numbers from 6 to 2000 are

6, 8, 10, . . . . 2000

After observing the above list of the even numbers from 6 to 2000 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 6 to 2000 form an Arithmetic Series.

In the Arithmetic Series of the even numbers from 6 to 2000

The First Term (a) = 6

The Common Difference (d) = 2

And the last term (ℓ) = 2000

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 2000

= 6 + 2000/2

= 2006/2 = 1003

Thus, the average of the even numbers from 6 to 2000 = 1003 Answer

Method (2) to find the average of the even numbers from 6 to 2000

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

The even numbers from 6 to 2000 are

6, 8, 10, . . . . 2000

The even numbers from 6 to 2000 form an Arithmetic Series in which

The First Term (a) = 6

The Common Difference (d) = 2

And the last term (ℓ) = 2000

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 2000

2000 = 6 + (n – 1) × 2

⇒ 2000 = 6 + 2 n – 2

⇒ 2000 = 6 – 2 + 2 n

⇒ 2000 = 4 + 2 n

After transposing 4 to LHS

⇒ 2000 – 4 = 2 n

⇒ 1996 = 2 n

After rearranging the above expression

⇒ 2 n = 1996

After transposing 2 to RHS

⇒ n = 1996/2

⇒ n = 998

Thus, the number of terms of even numbers from 6 to 2000 = 998

This means 2000 is the 998th term.

Finding the sum of the given even numbers from 6 to 2000

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 2000

= 998/2 (6 + 2000)

= 998/2 × 2006

= 998 × 2006/2

= 2001988/2 = 1000994

Thus, the sum of all terms of the given even numbers from 6 to 2000 = 1000994

And, the total number of terms = 998

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 2000

= 1000994/998 = 1003

Thus, the average of the given even numbers from 6 to 2000 = 1003 Answer


Similar Questions

(1) Find the average of the first 2844 even numbers.

(2) Find the average of even numbers from 6 to 1128

(3) Find the average of odd numbers from 11 to 1085

(4) Find the average of odd numbers from 9 to 305

(5) Find the average of the first 2935 odd numbers.

(6) Find the average of the first 1471 odd numbers.

(7) Find the average of the first 4289 even numbers.

(8) Find the average of the first 290 odd numbers.

(9) Find the average of odd numbers from 15 to 1053

(10) Find the average of the first 1480 odd numbers.


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