I like to think of the 1st question differently. From my what I learned about circular permutation, we can think of it as linear arrangement but we've overcounted by the possible rotations. We can rotate the table in such possible arrangement, and it happens 'n times for n seats'. I'd like check my understanding here, I'll be glad if anyone could help... So what I did was (for the 1st question)-- First I considered linear arrangements, I came up with 2 possible cases - MenWomenMean...+ WomenMenWomen... And divided by 8 (8 seats) And got the same answer I just wanted to check if theres something wrong with my logic
I'm still a little confused as to why you don't divide by 8 on the first one. Wouldn't it be a different arrangement if each individual shifted over by one?
Think it this way. What if the table wasn't a circular one but a straight one? In that case, the number of possible arrangement would be 2*4!*4!*. The 2 accounts for the fact that you could start the arrangement either with a man or a woman. So 2 ways. Now when you think of a circular table, you have to consider Rotational Symmetry( That's the key term). For 8 people we have 8 rotational symmetry,right? So you actually divide up everything by 8. You have 144.
Hi sir or anyone can you tell me the answer for this question. A coach has 16 players and can pick from 11 players for a match. it consist of 7 specialist batsmen, 4 fast bowlers, 3 spinner and 2 wicketkeeper. how many different teams can be formed if it must comprised of 6 specialist batsmen, 3 fast bowlers , 1 spinner and a wicketkeeper.
@@HHH21 No, that's wrong. The correct one is the answer by @Oli Wood, because if you choose 11 players from 16, then this also has the possibility to pick all 7 specialist batsmen and all 4 fast bowlers and one of the others.
@@mynameisjeff9124 How can you pick from only 11 players if total are 16? And there isn't any possibility to pick all 7 batsman and more because restrictions are already given
Second problem is not right, we can prove it easily by stating the problem as: A bookshelf has 5 fiction books and 6 non-fictioon books. In how many ways can we choose two books of each type? the answer is not 150. the equation for the original question is simply 6x=150
The answer in the vedio is correct. There are 5 non fiction books. That equation you're talking about is wrong, because what is x supposed to represent
@@danielknutson8238 yeah he did that too but if you saw the video he first found out the number of possibilities, then took out the probability. Number of possibilities are 2x26C5 and probability is just that divided by all possibilities i.e. 52C5. These we get by the basic combination formula of choosing r things out of n distinct things. What I don’t understand is the first one. There’s something called the 8 way symmetry of a circle and if you think about it. 4! X 4! should be divided by 8 because all 8 places are identical in a circle but it’s not. Why is that?
@@danielknutson8238 wasnt the question asking frlor how many HANDS have cards all the same colour? So why did he solve it like that. Wouldnt u need to divide the 26 by 5