If the number 2345a60b is exactly divisible by 3 and 5, then the maximum value of a + b is _________.

If the number 2345a60b is exactly divisible by 3 and 5, then the maximum value of a+b is ___.
Given the data,
2345a60b is exactly divisible by 3 and 5.
In the divisibility rule of 3 and 5,
The number is completely divisible by 3 if the sum of the digits is divisible by 3.
The number is completely divisible by 5 if the last digit of the given number is 0 or 5.
Therefore, the value of b must be 0 or 5, as b is the last digit of the given number.
a + b has to be maximum, so b will be 5.
Substituting the value of b,
We got 2345a605.
Now, add the digits 2345a605,
$\Rightarrow$2 + 3 + 4 + 5 + a + 6 + 0 + 5
$\Rightarrow$25 + a
If we add 2, 5, or 8 in 25 we get a number greater than 25 and divisible by 3.
As, we need the maximum value of a.
Thus, the value of ‘a’ will be 8.
Now, calculating the value of a+b.
Substituting the values,
a + b = 8 + 5
a + b =13
Hence, the value of a + b is 13.