Question:
Find the average of even numbers from 8 to 1296
Correct Answer
652
Solution And Explanation
Solution
Method (1) to find the average of the even numbers from 8 to 1296
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 8 to 1296 are
8, 10, 12, . . . . 1296
After observing the above list of the even numbers from 8 to 1296 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 8 to 1296 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 8 to 1296
The First Term (a) = 8
The Common Difference (d) = 2
And the last term (ℓ) = 1296
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 8 to 1296
= 8 + 1296/2
= 1304/2 = 652
Thus, the average of the even numbers from 8 to 1296 = 652 Answer
Method (2) to find the average of the even numbers from 8 to 1296
Finding the average of given continuous even numbers after finding their sum
The even numbers from 8 to 1296 are
8, 10, 12, . . . . 1296
The even numbers from 8 to 1296 form an Arithmetic Series in which
The First Term (a) = 8
The Common Difference (d) = 2
And the last term (ℓ) = 1296
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 8 to 1296
1296 = 8 + (n – 1) × 2
⇒ 1296 = 8 + 2 n – 2
⇒ 1296 = 8 – 2 + 2 n
⇒ 1296 = 6 + 2 n
After transposing 6 to LHS
⇒ 1296 – 6 = 2 n
⇒ 1290 = 2 n
After rearranging the above expression
⇒ 2 n = 1290
After transposing 2 to RHS
⇒ n = 1290/2
⇒ n = 645
Thus, the number of terms of even numbers from 8 to 1296 = 645
This means 1296 is the 645th term.
Finding the sum of the given even numbers from 8 to 1296
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 8 to 1296
= 645/2 (8 + 1296)
= 645/2 × 1304
= 645 × 1304/2
= 841080/2 = 420540
Thus, the sum of all terms of the given even numbers from 8 to 1296 = 420540
And, the total number of terms = 645
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 8 to 1296
= 420540/645 = 652
Thus, the average of the given even numbers from 8 to 1296 = 652 Answer
Similar Questions
(1) Find the average of the first 4739 even numbers.
(2) What is the average of the first 98 even numbers?
(3) Find the average of even numbers from 10 to 1378
(4) Find the average of odd numbers from 15 to 235
(5) Find the average of the first 2558 even numbers.
(6) Find the average of odd numbers from 15 to 953
(7) Find the average of the first 3887 even numbers.
(8) Find the average of the first 2859 even numbers.
(9) Find the average of even numbers from 8 to 1246
(10) Find the average of even numbers from 12 to 654