Question:
Find the average of even numbers from 12 to 382
Correct Answer
197
Solution And Explanation
Solution
Method (1) to find the average of the even numbers from 12 to 382
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 12 to 382 are
12, 14, 16, . . . . 382
After observing the above list of the even numbers from 12 to 382 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 12 to 382 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 12 to 382
The First Term (a) = 12
The Common Difference (d) = 2
And the last term (ℓ) = 382
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 12 to 382
= 12 + 382/2
= 394/2 = 197
Thus, the average of the even numbers from 12 to 382 = 197 Answer
Method (2) to find the average of the even numbers from 12 to 382
Finding the average of given continuous even numbers after finding their sum
The even numbers from 12 to 382 are
12, 14, 16, . . . . 382
The even numbers from 12 to 382 form an Arithmetic Series in which
The First Term (a) = 12
The Common Difference (d) = 2
And the last term (ℓ) = 382
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 12 to 382
382 = 12 + (n – 1) × 2
⇒ 382 = 12 + 2 n – 2
⇒ 382 = 12 – 2 + 2 n
⇒ 382 = 10 + 2 n
After transposing 10 to LHS
⇒ 382 – 10 = 2 n
⇒ 372 = 2 n
After rearranging the above expression
⇒ 2 n = 372
After transposing 2 to RHS
⇒ n = 372/2
⇒ n = 186
Thus, the number of terms of even numbers from 12 to 382 = 186
This means 382 is the 186th term.
Finding the sum of the given even numbers from 12 to 382
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 12 to 382
= 186/2 (12 + 382)
= 186/2 × 394
= 186 × 394/2
= 73284/2 = 36642
Thus, the sum of all terms of the given even numbers from 12 to 382 = 36642
And, the total number of terms = 186
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 12 to 382
= 36642/186 = 197
Thus, the average of the given even numbers from 12 to 382 = 197 Answer
Similar Questions
(1) Find the average of odd numbers from 7 to 343
(2) Find the average of the first 627 odd numbers.
(3) Find the average of odd numbers from 9 to 457
(4) Find the average of the first 3696 odd numbers.
(5) Find the average of odd numbers from 11 to 613
(6) Find the average of odd numbers from 5 to 43
(7) Find the average of the first 1513 odd numbers.
(8) Find the average of the first 3327 odd numbers.
(9) Find the average of the first 2917 odd numbers.
(10) Find the average of the first 2765 even numbers.