Sum of first 20 natural numbers:
A420
B200
C220
D210
Answer & Solution
Correct answer: D. 210
1. Sum 1 to n = n(n+1)/2.
2. n = 20: 20·21/2 = 210.
_Source: TSICET 2024 PYQ Q.102 (Shift 1, AP)_
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