Level 48: Sum 1 + 3 + 5 + 7 + …. + 97 yes

The number of consecutive odd natural numbers from 1 to 97 is (97 – 1) : 2 = 49 numbers

Hence 1 + 3 + 5 + 7 + …. + 97 = \( {(97 + 1) . 49 \over 2}\)= 2401

So the sum to find has the last digit is 1

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