Question:
Find the average of even numbers from 6 to 404
Correct Answer
205
Solution And Explanation
Solution
Method (1) to find the average of the even numbers from 6 to 404
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 6 to 404 are
6, 8, 10, . . . . 404
After observing the above list of the even numbers from 6 to 404 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 6 to 404 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 6 to 404
The First Term (a) = 6
The Common Difference (d) = 2
And the last term (ℓ) = 404
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 404
= 6 + 404/2
= 410/2 = 205
Thus, the average of the even numbers from 6 to 404 = 205 Answer
Method (2) to find the average of the even numbers from 6 to 404
Finding the average of given continuous even numbers after finding their sum
The even numbers from 6 to 404 are
6, 8, 10, . . . . 404
The even numbers from 6 to 404 form an Arithmetic Series in which
The First Term (a) = 6
The Common Difference (d) = 2
And the last term (ℓ) = 404
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 404
404 = 6 + (n – 1) × 2
⇒ 404 = 6 + 2 n – 2
⇒ 404 = 6 – 2 + 2 n
⇒ 404 = 4 + 2 n
After transposing 4 to LHS
⇒ 404 – 4 = 2 n
⇒ 400 = 2 n
After rearranging the above expression
⇒ 2 n = 400
After transposing 2 to RHS
⇒ n = 400/2
⇒ n = 200
Thus, the number of terms of even numbers from 6 to 404 = 200
This means 404 is the 200th term.
Finding the sum of the given even numbers from 6 to 404
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 404
= 200/2 (6 + 404)
= 200/2 × 410
= 200 × 410/2
= 82000/2 = 41000
Thus, the sum of all terms of the given even numbers from 6 to 404 = 41000
And, the total number of terms = 200
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 404
= 41000/200 = 205
Thus, the average of the given even numbers from 6 to 404 = 205 Answer
Similar Questions
(1) Find the average of the first 4484 even numbers.
(2) Find the average of even numbers from 12 to 1272
(3) Find the average of even numbers from 10 to 394
(4) Find the average of the first 3826 odd numbers.
(5) What is the average of the first 1390 even numbers?
(6) What will be the average of the first 4514 odd numbers?
(7) Find the average of the first 4964 even numbers.
(8) Find the average of odd numbers from 3 to 71
(9) What will be the average of the first 4559 odd numbers?
(10) Find the average of even numbers from 6 to 794