Question

find the value of a in the number 45a364is divisible by 9

Answer 1

since it is divisible by 9 therefore sum of all the digits should be equal to one of the multiple of nine:
4+5+a+3+6+4=22
now nearest multiple to 22 is 27
so a=27-22=5
hence 5 is the answer

Answer 2

we know that ,

for a number to be divisible by 9 ,
their sum should be a multiple of 9

therefore,

$4 + 5 + a + 3 + 6 + 4 \\ = multiple \: of \: 9$

$22 + a \: = 27$

$a = 27 - 22$

$a = 5$