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The sum (101 + 102 + 103 +...... 200) is equal to :

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CCommunity
Right Answer for this question is 15025
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CCommunity
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