It's easier when you think about any base as the number of symbols a numeric system has, with a symbol representing zero included. When a position reachs the max of the symbols (in this case numbers) you reset that position back to zero and add one to the symbol on the left next to it. That's how 99+1=100.
Base 9 has nine symbols (from 0 to 8), so a 9 on base 9 would be 8+1=10. I mention it as "symbols" instead of numbers because in computers we use an hexadecimal numeric system (base 16), where symbols from 10 to 15 are represented by letters A to F. A 15=F in base 16 so a 17 would be F+2=11.
Just think of it as expansion of multiplication tables. If you're asked to convert any number to any basis then first split it into two numbers: one that can be divided by the basis and one which can't.
For example, convert 11412 to basis 7 be like 1141 (163x7) + 1. So then you divide 163 to be divisable by 7 again to get the remaining numbers, while placing 1 on the last digit. That's the 'manual' way of counting bases.
Secondly, there's the 'quick' way to count bases. If you remember the basis 10 rule, that every zero behind the first number means there's ten times the first number in total, in bases there's X+1 factor of the Y number after the last digit. That's where the multiplication table comes to play.
The answer is 3221! Once you learned how to do this quickly you can use this to create your own code language.
9+10 is basis 9 is not defined, because 9 is not a number in base 9. (only number from 0 to 8 exist, it go 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, etc)
Even if you pose that 9 is a synonyme for 10, the end result would be 20.
The question is in decimal which gets translated to base 9 in the answer(before or after calculations). So | 9+10 -> 10+11 = 21 | or |9 + 10 = 19 -> 21|. It's completely unreasonable to use both systems at the same time but jokes tend to be unreasonable. But honestly answering with a different base seems more of being a chaotic jerk than an idiot imo.
It's easier when you think about any base as the number of symbols a numeric system has, with a symbol representing zero included. When a position reachs the max of the symbols (in this case numbers) you reset that position back to zero and add one to the symbol on the left next to it. That's how 99+1=100.
Base 9 has nine symbols (from 0 to 8), so a 9 on base 9 would be 8+1=10. I mention it as "symbols" instead of numbers because in computers we use an hexadecimal numeric system (base 16), where symbols from 10 to 15 are represented by letters A to F. A 15=F in base 16 so a 17 would be F+2=11.
Oh man,I don't even learn this at school yet but thanks for the explanation
