Concept:The mean of a set of consecutive natural numbers from 1 to n is equal to the average of the first and the last number.
Explanation:The first ten natural numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
Their total sum is the sum of an arithmetic progression. The mean is found by dividing the sum by the count (10).
A shortcut: For consecutive numbers, mean = (first number + last number) / 2.
Here, first = 1 and last = 10. So mean = (1 + 10) / 2 = 11 / 2 = 5.5.
Answer:5.5 (Option B).