• # question_answer If $51x\text{ }3$is a multiple of 9, where x is a digit, then that is the value of x?

 We have, the sum of the digits of 51x 3=5+l+x+3=9+x Since, 51x 3 is divisible by 9. $\therefore$ (9+x) must be divisible by 9. $\therefore$(9 + x) must be equal to 0 or 9 or 18 or 27 or... But x is a digit, then $9+x=9\Rightarrow x=0$ $9+x=18\Rightarrow x=9$ $x=27\Rightarrow x=18,$which is not possible. $\therefore$ The required value of x = 0 or 9.