Think about it like this, if you want to roll a 1, you have a 1/6 chance to roll it since theres 6 faces on the die Therefore, the expected number of rolls needed to get a 1 is the inverse, i.e 6/1 or 6 rolls to roll a 1 The same logic is used when determining the expected number of rolls to get a number of equal or greater value of Xi For a more in depth solution on how this inverse idea works, check out: math.stackexchange.com/questions/42930/what-is-the-expected-value-of-the-number-of-die-rolls-necessary-to-get-a-specifi Let us know if that helps!
@@mathbrah yes! All questions we go over are commonly asked in quant interviews. There made to test your problem solving skills. This problem is an easy one, for harder questions check out the site quantquestions.io
Could you explain why the expected number of rolls needed is simply the inverse?
Think about it like this, if you want to roll a 1, you have a 1/6 chance to roll it since theres 6 faces on the die
Therefore, the expected number of rolls needed to get a 1 is the inverse, i.e 6/1 or 6 rolls to roll a 1
The same logic is used when determining the expected number of rolls to get a number of equal or greater value of Xi
For a more in depth solution on how this inverse idea works, check out:
math.stackexchange.com/questions/42930/what-is-the-expected-value-of-the-number-of-die-rolls-necessary-to-get-a-specifi
Let us know if that helps!
@@QuantQuestionsio Thank you! I appreciate the answer.
are these interview questions?
@@mathbrah yes! All questions we go over are commonly asked in quant interviews. There made to test your problem solving skills.
This problem is an easy one, for harder questions check out the site quantquestions.io