Quote:
The sum of the positive integers from 1 through n can be calculated by the formula n(n+1)/2. Which one of the following equals the sum of all the even numbers from 0 through 20, inclusive?
Required is to calculate: 0+2+4+6+.....+20
The given sequence is in Arithmetic Progression, in which Average = (first term + last term)/2 = (0+20)/2 = 10
Number of even readings from 0 to 20, inclusive are 11
As, Sum of readings = Average * Number of readings = 10*11 = 110
D is correct _________________
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