Sum of first 'n' natural numbers, divisibility : AP, Number Systems
The question a progressions question with a flavour of Number Systems with divisibility thrown in for good measure.
Question
The sum of the first 100 natural numbers, 1 to 100 is divisible by
- 2, 4 and 8
- 2 and 4
- 2
- 100
- None of these
Correct Answer -
2 . Choice (3)
Explanatory Answer
The sum of the first 100 natural numbers is

.
101 is an odd number and 50 is divisible by 2.
Hence, 50*101 will be divisible by 2.
Correct answer choice (3)
Level of difficulty : Easy to Moderate
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