Question : Find the average of even numbers from 10 to 1944
Correct Answer 977
Solution & Explanation
Solution
Method (1) to find the average of the even numbers from 10 to 1944
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 10 to 1944 are
10, 12, 14, . . . . 1944
After observing the above list of the even numbers from 10 to 1944 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 10 to 1944 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 10 to 1944
The First Term (a) = 10
The Common Difference (d) = 2
And the last term (ℓ) = 1944
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 10 to 1944
= 10 + 1944/2
= 1954/2 = 977
Thus, the average of the even numbers from 10 to 1944 = 977 Answer
Method (2) to find the average of the even numbers from 10 to 1944
Finding the average of given continuous even numbers after finding their sum
The even numbers from 10 to 1944 are
10, 12, 14, . . . . 1944
The even numbers from 10 to 1944 form an Arithmetic Series in which
The First Term (a) = 10
The Common Difference (d) = 2
And the last term (ℓ) = 1944
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 10 to 1944
1944 = 10 + (n – 1) × 2
⇒ 1944 = 10 + 2 n – 2
⇒ 1944 = 10 – 2 + 2 n
⇒ 1944 = 8 + 2 n
After transposing 8 to LHS
⇒ 1944 – 8 = 2 n
⇒ 1936 = 2 n
After rearranging the above expression
⇒ 2 n = 1936
After transposing 2 to RHS
⇒ n = 1936/2
⇒ n = 968
Thus, the number of terms of even numbers from 10 to 1944 = 968
This means 1944 is the 968th term.
Finding the sum of the given even numbers from 10 to 1944
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 10 to 1944
= 968/2 (10 + 1944)
= 968/2 × 1954
= 968 × 1954/2
= 1891472/2 = 945736
Thus, the sum of all terms of the given even numbers from 10 to 1944 = 945736
And, the total number of terms = 968
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 10 to 1944
= 945736/968 = 977
Thus, the average of the given even numbers from 10 to 1944 = 977 Answer
Similar Questions
(1) Find the average of even numbers from 12 to 548
(2) Find the average of even numbers from 6 to 1262
(3) Find the average of the first 2421 even numbers.
(4) What is the average of the first 425 even numbers?
(5) Find the average of the first 731 odd numbers.
(6) Find the average of odd numbers from 5 to 723
(7) Find the average of the first 4988 even numbers.
(8) Find the average of odd numbers from 9 to 553
(9) Find the average of the first 2676 odd numbers.
(10) Find the average of odd numbers from 15 to 267