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Find the Sum of all natural numbers from 21 to 80 { ans 30, 30)Arithmetic equation |
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Answer» Answer: 3030 Step-by-step explanation: by a.p. series we KNOW the formula of sum of the a.p. series= N/2{2a+(n-1)d} where, a= first DIGIT in the series d=difference between the first TWO digits n= th term i.e,. 60/2{2×21+(60-1)1}= 30{42+59}=30×101=3030 |
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