What is the product of the largest and the smallest possible values of m for which a number 5m83m4m1 is divisible by 9?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 16.
Divisibility rule of 9: A number is divisible by 9 when the sum of the digits of the number is divisible by 9.
⇒ (5 + m + 8 + 3 + m + 4 + m + 1)
For minimum value = 21 + 3m
The minimum value of m = 2 (as 27 is the multiple of 9)
For maximum value = 21 + 3m
The maximum value of m = 8 (as 45 is the multiple of 9)
The product of the largest and smallest value
⇒ (8 × 2) = 16