Question

The six digit number 54321X is divisible by 9 where X is a single digit whole number. Find A.

Answer 1

NOW SEE .... FOR BEING DIVISIBLE BY 9 WE NEED A NUMBER DIVISIBLE BY 3×3.

. NOW

ADD ALL DIGITS TO CHECK DIVISIBILITY BY 9

5+4+3+2+1+X=15+X

NOW TO MAKE SUM DIVISIBLE BY 9

NEAREST WHOLE NO. TO 15 =18

15+X=18

X=3.....

HOPE IT HELPS....

Answer 2

I ff sum of digits is divisible by 9

then The given number is divisible by 9

5+4+3+2+x is divisible by 9

14+x is divisible by 9

by trial x=4

14+4=18which is divisible by 9

so x=4