Category: Permutation and Combination

Question Number 106792 by bobhans last updated on 07/Aug/20 $$\succ \mathrm{bobhans}\prec$$$$\mathrm{From}\mathrm{a}\mathrm{batch}\mathrm{containing}6\mathrm{boys}\mathrm{and}4\mathrm{girls}$$$$\mathrm{a}\mathrm{group}\mathrm{of}4\mathrm{students}\mathrm{is}\mathrm{tobe}\mathrm{selected}.$$$$\mathrm{How}\mathrm{many}\mathrm{group}\mathrm{formations}\mathrm{will}\mathrm{have}$$$$\mathrm{exactly}2\mathrm{girls}?$$ Answered by bemath last updated…

Question Number 171845 by Mikenice last updated on 21/Jun/22 $$n_{c_{r+1}}+n_{c_r}=n+1_{c_{r.solvefornandr.}}$$ Terms of Service Privacy Policy Contact: info@tinkutara.com

Question Number 106292 by bemath last updated on 04/Aug/20 $$\mathrm{a}\mathrm{box}\mathrm{contains}4\mathrm{blue},3\mathrm{green}\mathrm{and}2\mathrm{red}\mathrm{identicall}\mathrm{balls}.$$$$\mathrm{if}\mathrm{two}\mathrm{balls}\mathrm{are}\mathrm{selected}\mathrm{at}\mathrm{random}\mathrm{without}$$$$\mathrm{replacement},\mathrm{what}\mathrm{is}\mathrm{the}\mathrm{probability}$$$$\mathrm{that}\mathrm{two}\mathrm{balls}\mathrm{be}\mathrm{of}\mathrm{the}\mathrm{same}\mathrm{colours}?$$ Answered by bobhans last updated on 04/Aug/20…

Question Number 40550 by vajpaithegrate@gmail.com last updated on 24/Jul/18 $$\mathrm{if}\mathrm{three}\mathrm{numbers}\mathrm{are}\mathrm{drawn}\mathrm{at}\mathrm{random}$$$$\mathrm{successively}\mathrm{without}\mathrm{replacement}\mathrm{from}$$$$\mathrm{a}\mathrm{set}\mathrm{S}=\{1,2,\dots \dots 10\}\mathrm{then}\mathrm{probability}\mathrm{that}$$$$\mathrm{the}\mathrm{minimum}\mathrm{of}\mathrm{the}\mathrm{choosen}\mathrm{number}\mathrm{is}$$$$3\mathrm{or}\mathrm{their}\mathrm{maximum}\mathrm{is}7$$$$\mathrm{Answer}=\frac{11}{40}$$ Answered by tanmay.chaudhury50@gmail.com…

Question Number 105853 by bobhans last updated on 01/Aug/20 $$Aboxcontains5balls,2ballswere$$$$drawnatrandom,bothofwhich$$$$turnedouttobewhite.whatisthe$$$$probabilitythatalltheballsinthebox$$$$arewhite?$$ Commented by bobhans last updated…