Question

the sum of first 100 consecutive odd number is
a. 100
b. 1000
c. 10000
d. 100000

Answer 1

Sol)
The series go like :

1,3,5,7………,199

These numbers are in an Arithmetic Progression.

The sum of ‘n’ numbers in an A.P is S = n/2[2*a + (n -1 ) * d]

where n = number of terms, a = first term in the sequence , d is the common difference (2 in this particular case).

Putting everything in the formula S = 100/2[2*1 + (100 -1 ) * 2] = 10,000

So, 10,000 is your answer.