If x is a digit of the number ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯66784x such that it is divisible by 9, find the possible values of x.
5
∵ The number 66784x, is divisible by 9
∴ The sum of its digits will also be divisible by 9
⇒ 6+6+7+8+4+x is divisible by 9
⇒ 31+x is divisible by 9
Hence 31 + x = 9 , 18 , 27,36,45 ..........
If 31 + x = 9 then x = -22
If 31 + x = 18 then x = -13
If 31 + x = 27 then x = -4
If 31 + x = 36 then x = 5
If 31 + x = 45 then x = 14
From the above , only possible value of x = 5
∴ x = 5