@@lifegoeson6461 you didnt understand that the card combination can be 2 hearts and 3c at the same time and it is counted from 2 directions so subsracting 1 is needed but in this case it does a very negkigible change to the probability hence he ignored that not to just confuse the students
Correct P(AuB) = P(A) + P(B) - P(AnB) strictly. Although this may be outside the scope of this learning set. They are still using nCr notation instead of n above r in brackets notation after all, and adding in confusing notions of double counting might derail the learning somewhat.
Adrian Phillips 0 seconds ago Yes (as Xesonik has indicated). The probability calculation Mr Woo gives at 09:07 is incorrect because it double counts the 22,308 (13C2×13C3) combinations containing both two hearts and three clubs. At 08:15 Mr Woo’s question “what if it were _or_ instead of _and_ ?” is also ambiguous because he does not make clear at that stage if by “two hearts or three clubs” he means “exactly two hearts or exactly three clubs” or “at least two hearts or at least three clubs”. This confusion continues at 08:52 when Mr Woo says “I’ve already taken 13 out, right?” followed shortly at 08:56 by “I’ve taken 2 out”.
you are such an amazing teacher sir!!
For the "2H or 3C" scenario, should we also subtract the combination of "2H and 3C" from the sum of the favorable outcome since it's counted twice?
Nope , getting 2H or 3C are mutually exclusive events , no commonality between them . The card is either a heart or a club , can't be both
@@lifegoeson6461 you didnt understand that the card combination can be 2 hearts and 3c at the same time and it is counted from 2 directions so subsracting 1 is needed but in this case it does a very negkigible change to the probability hence he ignored that not to just confuse the students
Correct
P(AuB) = P(A) + P(B) - P(AnB) strictly.
Although this may be outside the scope of this learning set. They are still using nCr notation instead of n above r in brackets notation after all, and adding in confusing notions of double counting might derail the learning somewhat.
Adrian Phillips
0 seconds ago
Yes (as Xesonik has indicated).
The probability calculation Mr Woo gives at 09:07 is incorrect because it double counts the 22,308 (13C2×13C3) combinations containing both two hearts and three clubs.
At 08:15 Mr Woo’s question “what if it were _or_ instead of _and_ ?” is also ambiguous because he does not make clear at that stage if by “two hearts or three clubs” he means “exactly two hearts or exactly three clubs” or “at least two hearts or at least three clubs”. This confusion continues at 08:52 when Mr Woo says “I’ve already taken 13 out, right?” followed shortly at 08:56 by “I’ve taken 2 out”.
The indians are sugesting us to calculate this manually 😂
why did you sue combinations instead of permutations
It doesn't matter what order you pick the cards