Question : Find the average of odd numbers from 7 to 1467
Correct Answer 737
Solution & Explanation
Solution
Method (1) to find the average of the odd numbers from 7 to 1467
Shortcut Trick to find the average of the given continuous odd numbers
The odd numbers from 7 to 1467 are
7, 9, 11, . . . . 1467
After observing the above list of the odd numbers from 7 to 1467 we find that the difference between two consecutive terms are equal. This means the list of the odd numbers from 7 to 1467 form an Arithmetic Series.
In the Arithmetic Series of the odd numbers from 7 to 1467
The First Term (a) = 7
The Common Difference (d) = 2
And the last term (ℓ) = 1467
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 7 to 1467
= 7 + 1467/2
= 1474/2 = 737
Thus, the average of the odd numbers from 7 to 1467 = 737 Answer
Method (2) to find the average of the odd numbers from 7 to 1467
Finding the average of given continuous odd numbers after finding their sum
The odd numbers from 7 to 1467 are
7, 9, 11, . . . . 1467
The odd numbers from 7 to 1467 form an Arithmetic Series in which
The First Term (a) = 7
The Common Difference (d) = 2
And the last term (ℓ) = 1467
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 7 to 1467
1467 = 7 + (n – 1) × 2
⇒ 1467 = 7 + 2 n – 2
⇒ 1467 = 7 – 2 + 2 n
⇒ 1467 = 5 + 2 n
After transposing 5 to LHS
⇒ 1467 – 5 = 2 n
⇒ 1462 = 2 n
After rearranging the above expression
⇒ 2 n = 1462
After transposing 2 to RHS
⇒ n = 1462/2
⇒ n = 731
Thus, the number of terms of odd numbers from 7 to 1467 = 731
This means 1467 is the 731th term.
Finding the sum of the given odd numbers from 7 to 1467
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 7 to 1467
= 731/2 (7 + 1467)
= 731/2 × 1474
= 731 × 1474/2
= 1077494/2 = 538747
Thus, the sum of all terms of the given odd numbers from 7 to 1467 = 538747
And, the total number of terms = 731
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 7 to 1467
= 538747/731 = 737
Thus, the average of the given odd numbers from 7 to 1467 = 737 Answer
Similar Questions
(1) Find the average of even numbers from 6 to 1602
(2) What will be the average of the first 4655 odd numbers?
(3) Find the average of the first 3535 even numbers.
(4) Find the average of odd numbers from 13 to 91
(5) Find the average of odd numbers from 7 to 939
(6) Find the average of odd numbers from 5 to 697
(7) What will be the average of the first 4316 odd numbers?
(8) Find the average of even numbers from 10 to 442
(9) Find the average of even numbers from 4 to 1646
(10) Find the average of odd numbers from 15 to 825