How do you calculate 1+2+3+4+5+6+7+8+9+10 quickly?

Answer: 55

Explanation: Answer : 55 The series “1+2+3+4+5+6+7+8+9+10” can be considered as the sum of the first 10 Natural numbers. The generalized formula to find the sum of first N natural numbers is (N * (N + 1) ) /2 For the series given, the value of N is 10 So substituting value of N in the generalized formula ( 10 * (10 + 1) ) / 2 = (10 * 11 ) / 2 = 110/2 Correct answer = 55