Question

Which of the following numbers are divisible by $9$?
$369,1008,753321$

Answer 1

According to the divisibility test a number is divisible by $9$ if the sum of all its digits is divisible by $9$.

Given the numbers are $369,1008,753321$.

For $369$, the sum of digits is $=3+6+9=18$, divisible by $9$ so the number is also divisible by $9$.

For $1008$, the sum of digits is $=1+0+0+8=9$, divisible by $9$ so the number is also divisible by $9$

For $753321$, the sum of digits is $=7+5+3+3+2+1=21$, not divisible by $9$ so the number is not divisible by $9$