This is a free lesson from our course in Algebra II
In this section you'll explore how
combinations and permutations concepts can be used to compute
probabilities. It is explained using some examples with solution, with the help of audio, video presentation
and
in instructor's own hand writing. Simply saying
probability is an estimate of frequency of an outcome in repeated trials. The probability of event A is the number of ways event A can occur divided by the total number of possible outcomes. Probability will always be a fraction, 0, or 1. If an event cannot happen, the probability is 0. If an event is certain to happen, the probability is 1.
Let P(E) = probability of an event E
n(E) = the number of elements in E
n(S) = the number of elements in sample space
The relationship is expressed by P(E)= n(E)/ n(S) and 0 = P(E) =1.
(More text below video...)
(Continued from above)
Remember about probability:
• P(E) = 0 in case of no outcome
• P(E) = 1 when the event is sample space
• P(E) + P(not E) = 1
• If P(E) = p, then P(not E) = 1  p
• In case of probability form of counting principle: If E_{1} & E_{2}
are independent events, and if P(E_{1}) = p and P(E_{2})
= q, then the probability of both E_{1} and E_{2} occurring
is p x q.
For example: If the letters of the word CABIN are rearranged at random, the theoretical
probability that one arrangement chosen at random will begin and end
with a vowel is, 1/10.
Winpossible's online math courses and tutorials have gained rapidly popularity since
their launch in 2008. Over 100,000 students have benefited from Winpossible's courses...
these courses in conjunction with free unlimited homework help serve as a very effective
mathtutor for our students.

All of the Winpossible math tutorials have been designed by topnotch instructors
and offer a comprehensive and rigorous math review of that topic.

We guarantee that any student who studies with Winpossible, will get a firm grasp
of the associated problemsolving techniques. Each course has our instructors providing
stepbystep solutions to a wide variety of problems, completely demystifying the
problemsolving process!

Winpossible courses have been used by students for help with homework and by homeschoolers.

Several teachers use Winpossible courses at schools as a supplement for inclass
instruction. They also use our course structure to develop course worksheets.