Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ ¹ ² ³ °
 

You are not logged in. Post a replyTopic review (newest first)
gOt it
Start with the first two numbers and end with the last two, listing each combination.
Hmm, and the rows are obtained how?
Hi, and for any n
Hi; ways. The standard way now to do this is to look at the ordered pairs. There is 1 way for 2 to be the maximum and 2 ways for 3 to be the maximum and there are generally m1 ways for m to be the maximum. Using the formula for expected value or expected number: For the second part, you do it in the same way. There are still n (n1)/2 ways to arrange n numbers with high and low. Now you go through the numbers in the same way. 1 is the lowest n1 times. 2 is the lowest n  2 times. n can never be the lowest. n1 is the lowest one time so generally m is lowest n  m times. We use the same formula for expected value: Now for the difference. Just subtract the expected value of the lowest from the highest. The absolute value is implied in there. When you have time please sign up over here: https://brilliant.org/
Explain in simple words please
That does suggest without replacement. The answer is (59 + 1 ) / 3 = 20.
"The teacher picks out two tickets"
If there picking without replacement then the answer is 20. If not the answer in post #2 holds.
I am getting 20 as well.
There is no replacement?
I am getting 20
Hi;
A school is running a raffle for two prizes. 59 tickets were sold for the raffle, numbered 1,…,59. All the tickets are put into a hat and a teacher picks out two tickets which have numbers i and j from the hat. What is the expected value of i−j? 