If the five digit number aa448 is divisible by 9, what digit does a represent?

a represent 1

and number is 11448.

Step-by-step explanation:

We know that a number is divisible by 9 if the sum of its digit is divisible by 9.

Given number aa448

sum of 4+4+8 = 16

number divisible by 9, 18 , 27,36

as we see sum of 448 is 16 , hence sum of a+a+4+4+8 should be  number divisible by 9 and greater than 16 which is 18, 27,36

Let see of if sum of digits of aa448 is divisible by  18

a+a+4+4+8 = 18

2a + 16 = 18

2a = 18-16 = 2

a =2/2 = 1

Thus, number will be 11448

Let see of if sum of digits of aa448 is divisible by  27

a+a+4+4+8 = 27

2a  = 27 - 16

2a = 11 = 2

a =11/2 = 5.5

as digit cannot be fraction of decimal, it can take value from 1 to 9 hence

sum of digits of aa448 is not divisible by  27

Let see of if sum of digits of aa448 is divisible by  36

a+a+4+4+8 = 36

2a + 16 = 36

2a = 36-16 = 20

a =20/2 = 10

as digit can take value from 1 to 9 hence sum of digits of aa448 cannot  be divisible by  36 or any higher number than 36 which is divisible by 9.

Thus , a represent 1

and number is 11448.