Question:
Find the average of odd numbers from 13 to 607
Correct Answer
310
Solution And Explanation
Solution
Method (1) to find the average of the odd numbers from 13 to 607
Shortcut Trick to find the average of the given continuous odd numbers
The odd numbers from 13 to 607 are
13, 15, 17, . . . . 607
After observing the above list of the odd numbers from 13 to 607 we find that the difference between two consecutive terms are equal. This means the list of the odd numbers from 13 to 607 form an Arithmetic Series.
In the Arithmetic Series of the odd numbers from 13 to 607
The First Term (a) = 13
The Common Difference (d) = 2
And the last term (ℓ) = 607
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 odd numbers from 13 to 607
= 13 + 607/2
= 620/2 = 310
Thus, the average of the odd numbers from 13 to 607 = 310 Answer
Method (2) to find the average of the odd numbers from 13 to 607
Finding the average of given continuous odd numbers after finding their sum
The odd numbers from 13 to 607 are
13, 15, 17, . . . . 607
The odd numbers from 13 to 607 form an Arithmetic Series in which
The First Term (a) = 13
The Common Difference (d) = 2
And the last term (ℓ) = 607
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 odd numbers from 13 to 607
607 = 13 + (n – 1) × 2
⇒ 607 = 13 + 2 n – 2
⇒ 607 = 13 – 2 + 2 n
⇒ 607 = 11 + 2 n
After transposing 11 to LHS
⇒ 607 – 11 = 2 n
⇒ 596 = 2 n
After rearranging the above expression
⇒ 2 n = 596
After transposing 2 to RHS
⇒ n = 596/2
⇒ n = 298
Thus, the number of terms of odd numbers from 13 to 607 = 298
This means 607 is the 298th term.
Finding the sum of the given odd numbers from 13 to 607
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 odd numbers from 13 to 607
= 298/2 (13 + 607)
= 298/2 × 620
= 298 × 620/2
= 184760/2 = 92380
Thus, the sum of all terms of the given odd numbers from 13 to 607 = 92380
And, the total number of terms = 298
Since, the average of the given numbers
= Sum of the given numbers/Total number of given numbers
Thus, the average of the given odd numbers from 13 to 607
= 92380/298 = 310
Thus, the average of the given odd numbers from 13 to 607 = 310 Answer
Similar Questions
(1) Find the average of odd numbers from 15 to 1153
(2) What will be the average of the first 4602 odd numbers?
(3) What is the average of the first 95 even numbers?
(4) Find the average of odd numbers from 9 to 885
(5) Find the average of even numbers from 12 to 1876
(6) What is the average of the first 472 even numbers?
(7) Find the average of even numbers from 6 to 204
(8) Find the average of odd numbers from 9 to 241
(9) Find the average of the first 2451 odd numbers.
(10) Find the average of odd numbers from 9 to 1105