Question

If 36x52y8 is divisible by 9, then x+y is

Answer 1

Answer:

3x+y= 3 divisibility test of 9

Answer 2

Answer:

The value of $x+y$ can be 3 or 12.  

Step-by-step explanation:

Given a number 36x52y8 is divisible by 9

From the divisibility rule of 9, "if the sum of digits of a number is divisible by 9, then the number itself is divisible by 9".

The sum of digits of 36x52y8 is

$3+6+x+5+2+y+8$

$=24+x+y$

If the number is divisible by 9, then $24+x+y$ must be a multiple of 9.

Therefore, if $24+x+y=27$, then $x+y=27-24=3$

If $24+x+y=36$, then $x+y=36-24=12$

And if $24+x+y=45$, then $x+y=45-24=21$

Since the sum of single digit numbers cannot go beyond 18, it is not possible for next multiples,

Therefore $x+y$ may have the value 3 or 12.