A certain spinner has equally sized slices. The odds in favor of landing on a red slice are 4 : 3. What is the probability of landing on a red slice?

The odds given are 4:3 in favor of landing on a red slice. This means that for every 4 times it lands on a red slice, it lands 3 times on a non-red slice.

Step 1: Add the two parts of the ratio to find the total number of outcomes. 4 (red) + 3 (not red) = 7 (total outcomes).

Step 2: The probability of an event is defined as the number of ways it can happen divided by the total number of outcomes. So, the probability of landing on a red slice is 4 (ways it can happen) divided by 7 (total outcomes).

Step 3: Therefore, the probability of landing on a red slice is 4/7.