Please explain the answer so I can understand:

Consider this algorithm Mid(a,b):

Input: two integers a and b

Output: an integer that is the midpoint between a and b (i.e., within equal distance from a and b).

Example: Mid(4,10) = 7

Mid(a,b)

m = (a + b) / 2

return m

1. Is this algorithm correct? (Answer only Yes or No)

Whatever is your answer, prove it using the fastest method: a counterexample. A proof by contradiction, or a proof by induction.