Let us Assume that p and q be the statements given by
p: x and y are integers and xy is an even integer.
q: At least one of x and y is even.
Let p be true, then xy is an even integer. So,
xy = 2(n + 1)
Now,
Let x = 2(k + 1)
Now as x is an even integer, xy = 2(k + 1). y is also an even integer.
Now take x = 2(k + 1) and y = 2(m + 1)
xy = 2(k + 1).2(m + 1) = 2.2(k + 1)(m + 1)
Therefore, it is also true.
Hence, the statement is true.