An encryption algorithm generates a seed value \(z\) in the following way:
A binary operator is chosen at random from \(\{+,\,\cdot\}\);
Two distinct numbers \(x\) and \(y\) are chosen at random from the set \(\{1,\,2,\,...,\,9\}\) and the binary operation chosen above acts on \(x\) and \(y\) to produce \(z\).
- What is the probability that \(z\) is an even number?
- You notice that the algorithm generates an even \(z\) value. Given this, what is the probability that the \(+\) operator was used to generate it?