Solve system of equations to get \((\frac{1}{3}, 2\sqrt{3})\), so \(b = 2\sqrt{3}\)
The denominator would be \(5\cdot5=25\). The only ways that the product is less than 4 is when they choose (1, 1) (1, 2), (1, 3), (2, 1), and (3, 1), which is 5 cases. So, \(25 - 5 = 20\), so the answer is \(\frac{20}{25} = \frac{4}{5}\).