The probability that it rains on a given day is 0.4, and the probability that a certain sports team wins on a given day is 0.7,…

For independent events, the probability that both occur is the product of their individual probabilities: $P(\text{rain and win}) = 0.4 \times 0.7 = 0.28$. Independence is stated in the problem, so the weather does not change the team's chance of winning. A common wrong answer is 1.1, which comes from adding the probabilities, $0.4 + 0.7$, a result greater than 1, which is impossible for a probability. Another is 0.7, which ignores the rain condition. A third is 0.18, from $0.4 \times 0.3$, which uses the chance of losing. Multiply for "and" with independent events.