Does the arithmetic operation -
102 (base 10)- 39 (base 10), represented in 8-bit, when converted to binary have an overflow or underflow?
My Ans - It has no problem. I mean there is neither overflow nor underflow because 8- bit numbers can range from -127 to +127. The answer to the binary operation is +63 and so it is within the range. Hence there is no over flow or under flow. Is my answer correct?
Yes, you are entirely correct.
There would certainly be overflow if we were adding $39_{10}$ to $102_{10}$ in two's complement, since the sum exceeds $127$, which is the maximum positive base 10 value representable in two's complement. However, there is no problem whatsoever when subtracting $39_{10}$ from $102_{10}$.