Alex chooses a number at random from the set {1, 2, 3, 4, 5}. Winnie also chooses a number at random from the same set. (They can choose the same number.) What is the probability that the product of their numbers is at least 4?
The denominator would be 5⋅5=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 2025=45.
+1216 
