Question:
Find the average of even numbers from 12 to 494
Correct Answer
253
Solution And Explanation
Solution
Method (1) to find the average of the even numbers from 12 to 494
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 12 to 494 are
12, 14, 16, . . . . 494
After observing the above list of the even numbers from 12 to 494 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 12 to 494 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 12 to 494
The First Term (a) = 12
The Common Difference (d) = 2
And the last term (ℓ) = 494
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 494
= 12 + 494/2
= 506/2 = 253
Thus, the average of the even numbers from 12 to 494 = 253 Answer
Method (2) to find the average of the even numbers from 12 to 494
Finding the average of given continuous even numbers after finding their sum
The even numbers from 12 to 494 are
12, 14, 16, . . . . 494
The even numbers from 12 to 494 form an Arithmetic Series in which
The First Term (a) = 12
The Common Difference (d) = 2
And the last term (ℓ) = 494
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 494
494 = 12 + (n – 1) × 2
⇒ 494 = 12 + 2 n – 2
⇒ 494 = 12 – 2 + 2 n
⇒ 494 = 10 + 2 n
After transposing 10 to LHS
⇒ 494 – 10 = 2 n
⇒ 484 = 2 n
After rearranging the above expression
⇒ 2 n = 484
After transposing 2 to RHS
⇒ n = 484/2
⇒ n = 242
Thus, the number of terms of even numbers from 12 to 494 = 242
This means 494 is the 242th term.
Finding the sum of the given even numbers from 12 to 494
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 494
= 242/2 (12 + 494)
= 242/2 × 506
= 242 × 506/2
= 122452/2 = 61226
Thus, the sum of all terms of the given even numbers from 12 to 494 = 61226
And, the total number of terms = 242
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 494
= 61226/242 = 253
Thus, the average of the given even numbers from 12 to 494 = 253 Answer
Similar Questions
(1) Find the average of even numbers from 4 to 156
(2) Find the average of odd numbers from 5 to 995
(3) What is the average of the first 1973 even numbers?
(4) Find the average of odd numbers from 5 to 609
(5) Find the average of the first 1713 odd numbers.
(6) Find the average of even numbers from 10 to 1968
(7) Find the average of odd numbers from 9 to 1339
(8) Find the average of the first 1839 odd numbers.
(9) Find the average of odd numbers from 5 to 855
(10) Find the average of the first 3412 even numbers.