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The sum of the first 10 odd natural numbers (1 + 3 + 5 + … + 19) is:
A{'text': '81'}
B{'text': '90'}
C{'text': '121'}
D{'text': '100'}
Answer & Solution
Correct answer: D. {'text': '100'}
1. The identity: sum of first n odd numbers = n².
2. Here n = 10, so the sum is 10² = 100.
3. Direct: 1+3+5+7+9+11+13+15+17+19 = 100 ✓.
4. Hence the answer is **100**.
_Source: Selina Concise ICSE Class 8 Mathematics Ch 3 "Squares and Square Roots", Sum of odd numbers property_
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