Example: Ways to arrange colors | Probability and combinatorics | Precalculus | Khan Academy

Thinking about how many ways you can pick four colors from a group of 6

Missed the previous lesson?

Precalculus on Khan Academy: You may think that precalculus is simply the course you take before calculus. You would be right, of course, but that definition doesn't mean anything unless you have some knowledge of what calculus is. Let's keep it simple, shall we? Calculus is a conceptual framework which provides systematic techniques for solving problems. These problems are appropriately applicable to analytic geometry and algebra. Therefore....precalculus gives you the background for the mathematical concepts, problems, issues and techniques that appear in calculus, including trigonometry, functions, complex numbers, vectors, matrices, and others. There you have it ladies and gentlemen....an introduction to precalculus!

About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.

For free. For everyone. Forever. #YouCanLearnAnything

Subscribe to Khan Academy’s Precalculus channel:

[mariagomez]

this is exactly what i needed. I'm tired of teachers just writing formulas for students to memorize instead of at least explaining the logic behind it...

[incitemylife]

I wish I could've gotten my degree from Khan Academy, he basically took the place of my professor through most of college.

[rochelleb]

you sir, are going to be the reason why I'm going to get a high grade in grade 12 data management. Thank you

[PsychYouOutlnTheEnd]

Good God, so much simpler than this textbook by my side. Thank you so much Khan Academy.

[xxktbby]

Studying for the GRE (Graduate Record Examination) in order to apply for Graduate school and I somehow find myself here....but Thanks! Works for all age groups!

[Dice-oeqr]

Finally this guy got his colors together!

[matthewlow]

everything just clicked when he explained it. Great channel!

[jonathanflores]

Very helpful and was easy to understand. Thank you!

[MadSpectro]

You're a better teacher than my Discrete Math professor.

[spamdude]

Where does this fit in your playlists? I don't think the website is updated yet.

[MsHani]

I've got an exam tomorrow and this video really helped.

[likkledee]

Only if this was a bit earlier, would have helped me in my 12th grade stats class.

[Fcreveryoung]

Also, if you were referring to the 6x5x4x3 step, then he stopped multiplying at three because the original problem stated that the solver could only choose a four section code. __x__x__x__ or 6x5x4x3

[demonshubham]

i also used to do like this memorising a formula is not d ultimate way!

[TasyaAdzkiya]

0:39 Well, I think it matters because the "The codemaker gives hints about whether the colors are correct and IN THE RIGHT POSITION." shows us that we can't mix it up (the order matters). Because if you are trying to decipher a code, the arrangement of the code has to be in order. For example, B L U E is different than U L E B although the letters are the same. That is a hint for us to use permutation instead of combination because order matters in permutation.

[burnsyy]

I'm pretty sure I failed my statistics mock exam.But now I have khan academy and 1 month to study.I'm gonna ace the finals.

[theunknown]

DUDE I have that game! :D the code breaker thing!

[dridrilife]

that makes sense but would it also be 6P4 ? then substitute it into the formula?

[jamesivan]

Hey, guys. can you help me out really quickly? In how many ways can seven students from a class of 30 be chosen for a field trip if Jack must go on the field trip. I'm assuming this is the same equation as 6 out of 29 students being chosen (29 nCr 6 on a graphing calculator). Is that correct? I'm assuming on the next question (what if Jack can't go on the trip) is the same formula. I just want to make sure I'm doing it right. Thanks, guys! You rock!

[kcrisos]

everyone commenting here has an upcoming test!