Math, asked by pooka1, 1 year ago

3से गुणा करके बनी 100 तथा 200 के बीच की सभी पाकृति क संख्या का योग क्या होगा ?

Answers

Answered by usp488
39
3 से गुणा करके बनी 100 से 200 के बीच की संख्याएँ 303, 306, 309................. अंतिम 597 होगी।
अब इनका जब योग होगा तो वह 44550 होगा।
Formula- n/2(first+last)

99/2(303+597)=44550

Thankyou

Hope it helps U :-)
Answered by throwdolbeau
45

Answer:

The required sum = 4950

Step-by-step explanation:

The required digits obtained are :

102, 105, 108, 111,...........,198

We need to find the sum of this sequence.

First term, a = 102

Common Difference, d = 3

\text{Last term, }a_n=198\\\\\text{To find the number of terms}\\\\a_n=a+(n-1)d\\\\\implies 198=102+(n-1)3\\\\\implies 96=(n-1)3\\\\\implies n-1=32\\\\\implies n = 33\\\\Now, S_n=\frac{n}{2}(a+a_n)\\\\\implies S_n=\frac{33}{2}\times (102+198)\\\\\implies S_n=\frac{33}{2}\times 300\\\\\implies S_n=4950

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