12 + 13 + 14 + ... 61 + 62 + 63 = ? Select the correct option:
A) 1361  B) 1362  C) 1950  D) 1364  E) 1365
Sum = 12 + 13 + 14 + ... 61 + 62 + 63   Sum of n consecutive positive integers starting from 1 is given as n(n+1)/2   Sum of first 63 positive integers = 63*64/2   Sum of first 11 positive integers = 11*12/2   Sum = 12 + 13 + 14 + ... 61 + 62 + 63 = 63*64/2 - 11*12/2= 
<gadget id="calculator">63*64/2 - 11*12/2</gadget>
<output>1_950</output>
1950   Answer : 1950
<result>C</result>
12 + 13 + 14 + ... 61 + 62 + 63 = ?