24 vote
The sum (101 + 102 + 103 +...... 200) is equal to :
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The sum (101 + 102 + 103 +...... 200) is equal to :
1). 15000
2). 15025
3). 15050
4). 25000
2 answers
3 vote
Right Answer for this question is 15025
59 vote
101 + 102 + 103 + .... + 200
S = (100 + 1) + (100 + 2) + (100 + 3) + ...+ (100 + 100)
Thus, it consists of 100 terms.
= (100 + 100 + 100 + .... 100 times) + (1 + 2 + 3 + ...... + 100)
= (100 × 100) + (1 + 2 + 3 + ..... + 100)
= (10000) + (1+ 2 + 3 + ... + 100)
= 10000 + 5050 = 15050
Here, a = 101, d= 102–101 = 1 =
200 an= a + (n – 1)d 200
= 101 + (n – 1)1 n – 1
= 99 $\frac{100}{2}$ {101+ 200}
= 50 × 301 = 15050
