CAT 2024 Quant Revision 🔴 Permutations and Combinations by Sayali Ma'am (2 Time CAT 99.97%iler)

[@radhekrishann-cg1jm]

Thank you, ma'am, for such a valuable session.

[@shivangiguneja4710]

Thanks for this session :)

[@CrackuInexam]

You're welcome! Make sure to practice these concepts!

[@Vibhanshurathaur2004]

Is this enough for permutations and combinations?

[@VinayB-t2u]

thank you so much mam for this session.

[@CrackuInexam]

You're welcome! We hope it was helpful.

[@Adrak29]

Could you please provide the link to your DILR workshop youtube video in which you covered cumulative and ranged data tables? Thank you!

[@CrackuInexam]

Top DILR sets: kzbin.info/www/bejne/hInHlIOfbJaUodk DILR revision videos: kzbin.info/aero/PLSjkMEhzZ_ifu04X1u8WhtOkyNwKhBvvp kzbin.info/www/bejne/iKPXn3iAnJ50bpY

[@GDPI]

When do we use n-1 C r-1 can you explain one more time somebody

[@shreyashsingh2228]

when each of the 'r' objects must have atleast 1 item (out of the 'n' items)

[@GDPI]

@ thanks

[@jollyjellyjigglybeans]

The derivation is actually pretty simple. It's called the balls and sticks method. Imagine that you have 'n' (i.e the sum) number of balls and 'r' number of sticks (i.e. number of addition symbols in the equation). Now if you arrange these balls and sticks, you would end up visually representing the equation and all the different cases. So the total number of arrangements would be the same as (n + r) objects where n are of one type and r are of a different type. = (n+r)!/n!r! = nCr Now if there are additional constraints stating that each variable must be at least 1 or 2 , or even say variable one must be at least x and variable 2 is atleast y, you can manipulate the equation as such: (for example) original equation => a + b + c = n Constraint says that 'a' needs to be at least 2 and 'b' needs to be at least 3. Then a = A + 2 and b = B + 3. => A + B + c = n - 5 Now applying the balls and sticks method would give the final answer.

[@GDPI]

@@jollyjellyjigglybeans thanks for explaining in detail

[@User9999-f9g]

Hello mam, watched this video and have noted the formula, but I could solve just one of the questions in the video, rest I couldn't. I'm giving dashcats and I'm unable to score good in quants. Any guidance you could provide as exam is approaching and I'm not scoring good enough. 😞

[@CrackuInexam]

Focus on a single topic or the topics you are already good at and get perfect in them. Don't try to learn any new concepts in these final days. But don't leave them out completely; at least learn the basics and concepts to answer any easy questions if there came any. All the best.

[@User9999-f9g]

@@CrackuInexam thank you mam. Should I continue giving mocks or should I revise entire quants at the moment?

[@CrackuInexam]

Give mocks until 20th. The last 3 days don't give mocks but revise all the topics and everything.

[@priyankabalmiki8266]

Hi, I"ve not watched any prior lecture on PnC. will it be advisable if I only watch this lecture & start practicing further?

[@CrackuInexam]

Yes, this gives a comprehensive view of everything for PnC, but it is also advisable to practice a good number of questions after you finish watching the video.