Reputation
Next tag badge:
99/100 score
25/20 answers
Badges
24 298 588
Newest
 Nice Answer
Impact
~5.8m people reached

Jul
4
comment Probability of drawing >18 when drawing 3 cards
Doable, but exceedingly messy. I would suggest doing a large simulation, and use the resulting frequencies as a table of values.
Jul
4
revised Erin rolls 4 four-sided dice all at once, then can roll a subset of her choosing a 2nd time. What is the probability of getting all the same number?
added 440 characters in body
Jul
4
answered Erin rolls 4 four-sided dice all at once, then can roll a subset of her choosing a 2nd time. What is the probability of getting all the same number?
Jul
4
comment Erin rolls 4 four-sided dice all at once, then can roll a subset of her choosing a 2nd time. What is the probability of getting all the same number?
The only thing that makes sense is that she leaves certain carefully selected dice as they fell, and tosses the rest, hoping that at the end all $4$ up faces will be the same,
Jul
4
comment ***M>N*** Find the ratio of M to N and hence find two possilbe sets of lengths for the sides
Seems kind of hard to find two,
Jul
4
comment Volumes of revolution (annular cross sections)
What you asked for has just been done in the answer by reluctant mathematician.
Jul
4
comment Volumes of revolution (annular cross sections)
Use the method of Cylindrical Shells. It can be done by slicing, but is more complicated that way.
Jul
4
comment Rotation of $y=x(1-x)$ about the $x$-axis
You are welcome.
Jul
4
comment Probability dealing with Odds
Let $p$ be the probability. Then $\frac{p}{1-p}=\frac{a}{b}$. Solve for $p$.
Jul
4
comment Rotation of $y=x(1-x)$ about the $x$-axis
This is the first volume calculation you met, $\int_0^1 \pi x^2(1-x)^2\,dx$. Expand and integrate.
Jul
4
revised Dice Roll Probabilities
deleted 24 characters in body
Jul
4
comment Probability of picking all white marbles?
There are $\binom{n}{k}$ equally likely ways to pick $k$ marbles. There are $\binom{5}{5}\binom{n-5}{k-5}$ ways to pick $5$ white and the rest non-white.
Jul
4
comment Probability of picking all white marbles?
I am having a bad day. Will delete, write a correct comment.
Jul
4
comment Probability of Probabilities :)
Yes, $32768$, enough to wallpaper a room. You are sure to win, and also sure to lose money, since the payoff for a winning ticket is undoubtedly much less than $32000$ to $1$.
Jul
4
comment Probability of Probabilities :)
$15$ matches, $2^{15}$ tickets.
Jul
4
reviewed Leave Open Doubt with Absolute Value Inequality
Jul
4
reviewed Leave Open Find the smallest natural number $n$
Jul
4
reviewed Leave Open compositions of n with k even summands and compositions of n-k with k odd summands
Jul
4
comment Distribution of Summation of two discrete random variables
Note that the support set for the sum is $7$ to $19$.
Jul
4
comment Dice Roll Probabilities
The problem was stated clearly, and that is exactly the problem that I solved.