# variable

1. ### Problem with arguing about probability mass of general random variable

(I'm not sure if this is the right sub-forum, but I didn't see a better fit.) I have a problem with an exercise in a machine learning text-book. Solving it doesn't require any knowledge of machine learning, though, just of advanced probability theory. It's a very simple exercise in principle...
2. ### Equation with natural variable

\lfloor n/1 \rfloor + \lfloor n/2 \rfloor +...+\lfloor n/(n-1) \rfloor =7\; , n-natural . To write it better : \sum_{j=1}^{n-1} \displaystyle \lfloor \frac{n}{j} \displaystyle \rfloor =7 \; ; n=? , Method Required !
3. ### 3 variable equations

Solve for positive integers : x+y+z=xyz .:cool: Method required !
4. ### How to take this variable out of this equation?

I'm working to develop a function in my embedded code for i2c initialization. I came up to this equation which is to calculate the speed of the i2c clock. But if I want to develop a function that takes a user popular numbers for speed then I have to change the shape of the equation to get...
5. ### Equation with complex variable

z=\ln x +i \pi x =0 . x=? , x\in \mathbb{R} .
6. ### Is the method to solve this single variable equation used correctly?

The problem is as follows: A king decides to split an award between his three best archers after organizing an accuracy contest in his court. The first one gets $\frac{2}{5}$ parts of the total minus $\frac{1}{5}$ of a pound, the second gets $\frac{2}{5}$ of the rest minus $\frac{1}{5}$ of a...
7. ### Calculate probability of interval with a random variable?

Hi! I have studied algebra and calculus mostly (Calculus 1), not so much probability. So my problem is that I have a random variable called r that can generate any number from 1 to 100 (1 and 100 are included, interval [1, 100]). I set up a condition that if r >= 1 and r <= 75 then generate a...
8. ### How can I calculate the joint probability for three variable?

I am a student studying the joint probability density function with multi variables. I understand how to obtain a joint probability density function when two uniform distributions have the following joint distribution like below. The distribution $f_V$(v) can be determined based on the...
9. ### Function Of Discrete Random Variable

Suppose you are playing a game that costs 8 dollars to play. You flip 10 coins and, for every head, you win 2 dollars. Whats the probability you lose money?