The four-digit number “25AB” is divisible by nine, with A the tens digit and B the units digit. How many different such four-digit numbers could “25AB” represent?
+118608
The four-digit number “25AB” is divisible by nine, with A the tens digit and B the units digit. How many different such four-digit numbers could “25AB” represent?
Well,
The four digits must add to a number that is divisable by 9.
A+B can be no more than 18
2+5=7
A+B+7 can be no more than 25
so
A+B+7=9 or 18
You can finish it. 
