Compound events example using diagram | Probability and combinatorics | Precalculus | Khan Academy

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[babybirdhome]

Guys, no, this one needs to be remade! Sal miscounted the columns and the answer is 15/24 = 5/8, not 12/24 = 1/2.

But in the meantime, this is a lesson for anyone who struggles with the concept-- even people who KNOW what they're doing still make mistakes sometimes, so don't be discouraged if you do too. :)

[theomnipresent]

I know it's been said already but to clarify...

at 1:54 you multiply 3 x 4 = 12;

but there are actually 3 rows & 5 columns, making it 3 x 5 = 15 !!!

Making the answer 15/24 which simplifies to 5/8; therefore P(5/8).

Please fix this; especially since the Khan Academy website references this video in its
Probabilities of compound Events lesson.

[robsim]

So, typically, on a four sided die, the result of the roll is the number which is oriented "up". A fair few examples can be found if you google image search "d4 die". Still, love your work! :)

[Allmula]

For a die not to show a 1, the 1 on both die must contact the rolling surface, this criterion is only met once out of the 24 possible outcomes, 1/24

[ShirakoTheFirst]

To go along with Konstantin, the probability is 15/24ths or 5/8ths Chance of not rolling a one.

[cheetahrice]

Its 3 by 5....how did you mess that up?

[jeromystewart]

Sal I thought you were infallible, I originally watched this on khanacademy.com and was questioning my sanity. it's 3x5 .. not 3x4 .. thanks for your great work Sal

[stanchik]

There are 5 columns selected making the probability 15/24

[aidenlashbrook]

ok i know everyone said it but just to be a jerk... its 3x5 not 3x4. you really need to fix this because well THEY USE THIS VIDEO AS A REFERANCE FOR THE LESSON.

[OriginalRipndip]

3*5 take your time and get it right Sal. u don't need to know everything. It sets a bad precedent.

[nismoflage]

How could you information that is not right ...
You need to review your topic before putting it on youtube .