Combinatorics: Examples, Equations, and Practice Problems

The range of probability for an event is $-1\le <!--\; \le \; -->P(E)\le <!--\; \le \; -->1$, where P(E) is the probability of the event. A)True
B)False

In how many different ways can 5 books be arranged on a shelf?

Suppose n is an integer such that the sum of the digits of n is 2, and ${10}^{10}<n<{10}^{11}$. The number of different values for n is: A)11 B)10 C)9 D)8

A box contains 3 blue, 2 white and 4 red marbles. If a marble is drawn at random from the box, what is the probability that it will not be a white marble? (a) 13, (b) 49, (c) 79, (d) 29

The sum of probabilities of all outcomes in an experiment is__.

If a coin is tossed twice what is the probability of getting two heads together

In a relay race,there are six teams A,B,C,D,E,F.(i)What is the probability that A,B,C,D finish first, second, third and fourth respectively.(ii)What is the probability that A,B,C and D are first four to finish(in any order).Assume that all finishing orders are equally likely.

What are the 4 Laws of Probability?

The total number of face cards in a deck of cards is?

How many red cards are present in a deck of cards?

The probability of drawing a black face card from a deck of 52 is 1/2. True or false

Red Widget Strategies wants to improve its customer service by being more efficient in how phone calls are processed. Toward that end, Red Widget does a statistical analysis of 1,000 outbound phone calls. The length of the calls is normally distributed, with a population mean = 240 seconds, and a population standard deviation = 40 second.
a. What is the probability that a particular call lasted less than 180 seconds?
b. What is the probability that a particular call lasted between 180 and 300 seconds?
c. What is the probability that a call lasted between 110 and 180 seconds?
d. What is the probability that a call lasted more than 300 seconds?

Why are metals a good conductor of electricity?

What does |dv/dt| and d|v|/dt represent . Can these be equal.

So, assume that $X$ and $Y$ are two random variables such that $Y=E[X|Y]$ almost surely and $X=E[Y|X]$ almost surely. We need to prove that $X=Y$ almost surely.

In the Georgia Pick 3 lottery game, you pay 51 cents to select a 3-digit number, such as 205.
Repetition of digits is allowed. If you select the same 3-digit number that is drawn, you win $356.
a) What is the probability you win the lottery?
b) What is the expected value of your winnings?

The probability of happening and event A is 0.5 and that of B is 0.3. If A and B are mutually exclusive events, then the probability of happening neither A nor B is

What does at least mean in probability?

Find the next three terms of the arithmetic sequence 19,24,29,34,...

On a normal standard die, one of the 21 dots from any one of the six faces is removed at random with each dot equally likely to be chosen. The die is then rolled. If the probability that the top face has an odd number of dots is p/q where p and q are in their lowest form, then the value of (p+q)/4 is