If 5A5 is 3-digit number divisible by 9, then find the value of digit A.
8
5A5 is a 3-digit number divisible by 9.
If a number is divisible by 9, then the sum of its digits will be divisible by 9.
⇒ 5 + A + 5 is divisible by 9.
⇒ 10 + A is a multiple of 9.
Here, A is a digit, so its value ranges from 0 to 9.
But if A = 9, 10 + 9 = 19, and 19 is not divisible by 9.
So now multiple of 9 which is greater than 10 but less than 19 is 18.
⇒ 10 + A = 18
⇒ A = 8
Hence, the number is 585.