If the number 58\(X\)31 is divisible by 9, where \(X\) is a digit, what is the value of \(X\)?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 1
A number is divisible by 9 when the sum of its digits is divisible by 9.
Digit sum \(=5+8+3+1+X=17+X\)
\(X\) is a digit from 0 to 9, so \(17+X\) lies between 17 and 26; the only multiple of 9 there is 18
\(X=18-17=1\)
The value of \(X\) is 1.
Why the other options are incorrect
Option (2) 2 — Incorrect. The digit sum would be 19, which is not a multiple of 9.
Option (3) 7 — Incorrect. The digit sum would be 24, which is not a multiple of 9.
Option (4) 4 — Incorrect. The digit sum would be 21, which is not a multiple of 9.