Find the sum of all natural numbers between 1 and 301 which are divisible by 11
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Answers
Answer:
4158
Step-by-step explanation:
The sum would be = 11 + 11 * 2 + 11 * 3 + . . .
Say the last number in this series = 11 * x.
So, 11 * x <= 301
=> x <= 27.36
=> x = 27
So, the required sum,
S = 11 + 11 * 2 + 11 * 3 + . . . + 11 * 27
= 11 (1 + 2 + 3 + ... + 27)
= 11 * (27*28)/2
= 4158
Given :
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- Sum of all natural numbers between 1 and 301 which are divisible by 11.
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To find :
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- The sum of all natural numbers between 1 and 301 which are divisible by 11.
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Let's understand :
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We're asked to find the sum of all natural numbers between 1 and 301 which are divisible by 11, We'll solve this using arithmetic progression, The formula is A(n) = a + (n-1)d, Here, an = 297, As it is the last number divisible by 11, a = 11, As it the first number divisible by 11 and d is equal to 11.
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According to the question,
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So, Let's apply the formula given below and find the sum,
⇝ A(n) = a + (n-1)d
⇝ 297 = 11 + (n - 1)11
⇝ 297 - 11 = (n - 1)11
⇝ 286 = (n - 1)11
⇝ n - 1 = 286/11
⇝ n - 1 = 26
⇝ n = 26 + 1
⇝ n = 27
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Now, For sum, We need to apply the formula given below,
- Sn = n/2 ( an+a)
By applying the formula, We get,
⇝ 27/2 ( 297 + 11)
⇝ 13.5(308)
⇝ 4158
Therefore, The sum of all natural numbers between 1 and 301 which are divisible by 11 is 4158.
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