Yes, the hexadecimal number 16.
D63A
The number 11, (in hexadecimal) is the letter 'b'
The decimal number 11 is equal to the hexadecimal number B.
Hexadecimal uses the digits 0-9 and the letters a-f (in either upper case A-F, or lower case a-f). You appear to have used a letter O in upper case and lower case (o). Neither is a valid [standard] hexadecimal digit; so 3EO and 3Eo both mean the same in hexadecimal: a non-valid number. 3E0 and 3e0 are both valid hexadecimal numbers that mean the same (as the decimal number 992). In C, to signify a hexadecimal number it is preceded by 0X or 0x (that is zero-letter X), as in 0x3E0, etc.
The decimal number 1976 is represented in hexadecimal as 7B8.
The value in hexadecimal of the decimal number 999910 is F41E6.
If you mean, for example, divide one hexadecimal number by another: In any number base, you can use basically the same method you use with decimal numbers - in the case of division, the "long division". However, you have to use the corresponding multiplication table, for example, the multiplication table for multiplying two hexadecimal digits, with a hexadecimal result.
F in hexadecimal is 17 in octal.
8 in octal, 16 in hexadecimal.
Write a program to convert a 2-digit BCD number into hexadecimal
15 in the hexadecimal number system is represented by 21 in the decimal system.