# List 'em Out!

**Number Theory**Level 4

Two numbers \(x\) and \(y\) are chosen at random without replacement from the first \(30\) natural numbers. the probability that \(x^{2} - y^{2}\) is divisible by \(3\) is given by \(\frac{a}{b}\). where a and b are co-prime to each other. Then \(a+b\) is equal to