The average of 9 consecutive natural numbers is 51. What is the smallest number among these numbers?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 47.
The nine consecutive natural numbers are x, (x + 1), (x + 2), (x + 3), (x + 4), (x + 5), (x + 6), (x + 7), (x + 8)
Sum = x + x + 1 + x + 2 + x + 3 + x + 4 + x + 5 + x + 6 + x + 7 + x + 8
⇒ (9x + 36)/9 = 51
⇒ 9x + 36 = 459
⇒ 9x = 423
⇒ x = 47
Hence, the smallest number is 47