 Consider an example. Let's say we have a user, user A, and they have chosen a random value between 1 and 10, inclusive. And in this case, let's say they chose a value 7. And we have another user, user B, who's trying to guess what value A chose. So B doesn't know that A chose 7. So what B can do is, given that it knows A chose between 1 and 10, is make guesses between 1 and 10. So let's say on the first attempt, they choose randomly between 1 and 10. If they get, maybe they choose 3 and they ask A, did you choose 3? And A says no. So B chooses again. And it doesn't choose 3 again. It selects from 1 and 10, but it will not use select 3 again. So maybe in the second attempt, they choose 5. And asks A, A says no. So B makes a third attempt and chooses 10. Asks A, A says no. I did not select 10. And on the fourth attempt, let's say B selects 7. They ask A, and A says yes. I selected 7. So in this case, B took four attempts. The first three were unsuccessful, and the last one was successful. Of course, B may have done it in a different way. B may have selected in an alternative case the values in a different order. So it may have selected 8 first and been unsuccessful. And then selected 1 and asked A, no. And keeps trying. 9, 4, unsuccessful. 3, 5, 6, still unsuccessful. 2, and 10, still unsuccessful. And now with Cho tried all numbers but 1. So B has finally tried the last number and says, did you select 7? And yes. We've finally got the value that Cho's. In this case, it took 10 attempts. And this is the worst case for B. 10 attempts, they had to try all values before they finally got there. So when we have 10 values to choose from, the worst case in the terms of the number of attempts is 10. Another scenario, maybe B chooses numbers in a different order again. Maybe the first number they choose is 7. In this case, they immediately get the correct answer. So in this case, we have one attempt, which is the best case. So the best case is when B chooses the value, which A also chose. Of course, B may choose in different order. And if we repeat this experiment multiple times, in the first experiment, they took 4 attempts. The second one, 10. The third one, 1 attempt. And we keep going. On average, the number of attempts that B is going to take is 5. That's the average case. And although we're not sure, so if we keep making random experiments, then 10% of the time it will be the best case. They'll choose it in the first instance. 1 attempt. 10% of the time it will take 2 attempts. 10% will take 3 attempts. And so on, until 10% of the time it will take 10 attempts. So the average number of attempts it will take is 5. The average of those values from 1 to 10.