Question

Fill in the blank with smallest digit to make $1234....67$ divisible by $9.$

Answer 1

Since as we know that sum of all digits of a number is divisible by $9$ then the number is also divisible by $9.$

The sum of all digits of a number $1234x67$ is $1+2+3+4+x+6+7=23+x$ , $23+x$is divisible by $9$ where $x$ is the smallest digit at blank space.

when $x=4$ then $23+4=27$which is divisible by $9.$

Hence, the smallest digit to be placed in blank space is $4$of number $725$…$26$ divisible by $9.$