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Category: Probability and Statistics

1-There-are-60-tickets-in-a-bag-numbered-1-through-60-If-a-ticket-is-picked-at-random-find-the-probability-that-the-number-is-divisible-by-3-or-4-

Question Number 27235 by das47955@mail.com last updated on 03/Jan/18 $$\left(\mathrm{1}\right)\:\:\boldsymbol{\mathrm{There}}\:\boldsymbol{\mathrm{are}}\:\mathrm{60}\:\boldsymbol{\mathrm{tickets}}\:\boldsymbol{\mathrm{in}}\:\boldsymbol{\mathrm{a}}\:\boldsymbol{\mathrm{bag}} \\ $$$$\boldsymbol{\mathrm{numbered}}\:\mathrm{1}\:\boldsymbol{\mathrm{through}}\:\mathrm{60}.\boldsymbol{\mathrm{If}}\:\boldsymbol{\mathrm{a}}\:\boldsymbol{\mathrm{ticket}}\: \\ $$$$\boldsymbol{\mathrm{is}}\:\boldsymbol{\mathrm{picked}}\:\boldsymbol{\mathrm{at}}\:\boldsymbol{\mathrm{random}},\boldsymbol{\mathrm{find}}\:\boldsymbol{\mathrm{the}}\: \\ $$$$\boldsymbol{\mathrm{probability}}\:\boldsymbol{\mathrm{that}}\:\boldsymbol{\mathrm{the}}\:\boldsymbol{\mathrm{number}}\:\boldsymbol{\mathrm{is}} \\ $$$$\boldsymbol{\mathrm{divisible}}\:\boldsymbol{\mathrm{by}}\:\mathrm{3}\:\boldsymbol{\mathrm{or}}\:\mathrm{4}\:? \\ $$ Answered by Rasheed.Sindhi last updated…

if-two-dice-are-tossed-together-what-is-probability-of-sim-of-number-on-the-dice-being-an-even-number-

Question Number 26255 by jashandhillon@gmail.com last updated on 23/Dec/17 $${if}\:{two}\:{dice}\:{are}\:{tossed}\:{together}\:{what}\:{is}\:{probability}\:{of}\:{sim}\:{of}\:{number}\:{on}\:{the}\:{dice}\:{being}\:{an}\:{even}\:{number} \\ $$ Commented by Rasheed.Sindhi last updated on 23/Dec/17 $$\mathrm{Sum}\:\mathrm{of}\:\mathrm{two}\:\mathrm{numbers}\:\mathrm{is}\:\mathrm{even}\:\mathrm{if}: \\ $$$$\:\mathrm{either}\:\mathrm{both}\:\mathrm{numbers}\:\mathrm{are}\:\mathrm{even} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{or}\:\mathrm{both}\:\mathrm{numbers}\:\mathrm{are}\:\mathrm{odd}. \\…

1-In-a-single-throw-of-three-dice-find-the-probability-of-getting-a-total-of-i-4-ii-at-most-4-iii-atleast-4-

Question Number 25559 by das47955@mail.com last updated on 11/Dec/17 $$\left(\mathrm{1}\right)\:\mathrm{In}\:\mathrm{a}\:\mathrm{single}\:\mathrm{throw}\:\mathrm{of}\:\mathrm{three}\: \\ $$$$\mathrm{dice},\mathrm{find}\:\mathrm{the}\:\mathrm{probability}\:\mathrm{of}\:\mathrm{getting} \\ $$$$\mathrm{a}\:\mathrm{total}\:\mathrm{of} \\ $$$$\left(\mathrm{i}\right)\:\mathrm{4} \\ $$$$\left(\mathrm{ii}\right)\:\mathrm{at}\:\mathrm{most}\:\mathrm{4} \\ $$$$\left(\mathrm{iii}\right)\:\mathrm{atleast}\:\mathrm{4} \\ $$ Commented by prakash…

The-mean-weights-of-three-groups-of-students-consisting-of-16-18-and-20-students-are-40-5kg-42-50kg-and-45-00kg-respectively-What-is-the-mean-weight-of-all-the-students-

Question Number 25549 by pieroo last updated on 11/Dec/17 $$\mathrm{The}\:\mathrm{mean}\:\mathrm{weights}\:\mathrm{of}\:\mathrm{three}\:\mathrm{groups}\:\mathrm{of}\:\mathrm{students} \\ $$$$\mathrm{consisting}\:\mathrm{of}\:\mathrm{16},\:\mathrm{18}\:\mathrm{and}\:\mathrm{20}\:\mathrm{students}\:\mathrm{are}\:\mathrm{40}.\mathrm{5kg},\:\mathrm{42}.\mathrm{50kg} \\ $$$$\mathrm{and}\:\mathrm{45}.\mathrm{00kg}\:\mathrm{respectively}.\:\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{mean}\:\mathrm{weight} \\ $$$$\mathrm{of}\:\mathrm{all}\:\mathrm{the}\:\mathrm{students}? \\ $$ Answered by Rasheed.Sindhi last updated on 11/Dec/17…

Question-90258

Question Number 90258 by jagoll last updated on 22/Apr/20 Commented by john santu last updated on 22/Apr/20 $$\left({a}\right){P}\left({X}\leqslant\mathrm{3}\right)\:=\:\underset{{k}\:=\:\mathrm{0}} {\overset{\mathrm{3}} {\sum}}{C}_{{k}} ^{\mathrm{25}} \left(\mathrm{0}.\mathrm{05}\right)^{{k}} \:\left(\mathrm{0}.\mathrm{95}\right)^{\mathrm{3}−{k}} \\ $$$$\left({b}\right){P}\left({X}\geqslant\mathrm{4}\right)\:=\:\mathrm{1}−\underset{{k}\:=\:\mathrm{0}}…

A-bag-contains-5-balls-2-green-and-3red-They-are-selected-without-replacement-till-the-remaining-balls-in-the-bag-are-of-same-colours-Let-the-random-variable-X-be-the-number-of-selections-possible-1

Question Number 90196 by Ar Brandon last updated on 21/Apr/20 $$\mathrm{A}\:\mathrm{bag}\:\mathrm{contains}\:\mathrm{5}\:\mathrm{balls},\:\mathrm{2}\:\mathrm{green}\:\mathrm{and}\:\mathrm{3red} \\ $$$$\mathrm{They}\:\mathrm{are}\:\mathrm{selected}\:\mathrm{without}\:\mathrm{replacement}\:\mathrm{till} \\ $$$$\mathrm{the}\:\mathrm{remaining}\:\mathrm{balls}\:\mathrm{in}\:\mathrm{the}\:\mathrm{bag}\:\mathrm{are}\:\mathrm{of}\:\mathrm{same}\:\mathrm{colours}. \\ $$$$\mathrm{Let}\:\mathrm{the}\:\mathrm{random}\:\mathrm{variable}\:\mathrm{X}\:\mathrm{be}\:\mathrm{the}\:\mathrm{number} \\ $$$$\mathrm{of}\:\mathrm{selections}\:\mathrm{possible} \\ $$$$\left.\mathrm{1}\right)\:\mathrm{Determine}\:\mathrm{the}\:\mathrm{set}\:\mathrm{of}\:\mathrm{values}\:\mathrm{of}\:\mathrm{X} \\ $$$$\left.\mathrm{2}\right)\mathrm{Determine}\:\mathrm{the}\:\mathrm{it}'\mathrm{s}\:\mathrm{expectation},\:\mathrm{its}\:\mathrm{variance} \\ $$$$\mathrm{and}\:\mathrm{its}\:\mathrm{standard}\:\mathrm{deviation}.…

I-hold-my-hand-behind-my-back-and-secretly-hold-up-n-fingers-0-n-5-I-then-as-you-am-I-holding-up-k-fingers-Where-k-is-also-a-random-number-0-k-5-You-randomly-guess-Yes-or-No-What-is-the-pr

Question Number 24490 by FilupES last updated on 19/Nov/17 $$\mathrm{I}\:\mathrm{hold}\:\mathrm{my}\:\mathrm{hand}\:\mathrm{behind}\:\mathrm{my}\:\mathrm{back},\:\mathrm{and}\:\mathrm{secretly} \\ $$$$\mathrm{hold}\:\mathrm{up}\:{n}\:\mathrm{fingers}\:\left(\mathrm{0}\leqslant{n}\leqslant\mathrm{5}\right). \\ $$$$\: \\ $$$$\mathrm{I}\:\mathrm{then}\:\mathrm{as}\:\mathrm{you},\:\mathrm{am}\:\mathrm{I}\:\mathrm{holding}\:\mathrm{up}\:{k}\:\mathrm{fingers}? \\ $$$$\mathrm{Where}\:{k}\:\mathrm{is}\:\mathrm{also}\:\mathrm{a}\:\mathrm{random}\:\mathrm{number}\:\mathrm{0}\leqslant{k}\leqslant\mathrm{5}. \\ $$$$\: \\ $$$$\mathrm{You}\:\mathrm{randomly}\:\mathrm{guess}\:\mathrm{Yes}\:\mathrm{or}\:\mathrm{No}. \\ $$$$\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{probability}\:\mathrm{you}\:\mathrm{guess}\:\mathrm{correctly}? \\…

In-a-classroom-when-the-students-sit-2-per-bench-11-students-are-left-with-no-sits-And-when-they-sit-3-per-bench-7-benches-are-left-empty-Determine-the-number-of-students-in-this-classroom-

Question Number 89898 by Ar Brandon last updated on 19/Apr/20 $${In}\:{a}\:{classroom}\:{when}\:{the}\:{students}\:{sit} \\ $$$$\mathrm{2}\:{per}\:{bench},\:\mathrm{11}\:{students}\:{are}\:{left}\:{with} \\ $$$${no}\:{sits}.\:{And}\:{when}\:{they}\:{sit}\:\mathrm{3}\:{per}\:{bench} \\ $$$$\mathrm{7}\:{benches}\:{are}\:{left}\:{empty}.\:{Determine}\:{the}\:{number} \\ $$$${of}\:{students}\:{in}\:{this}\:{classroom}. \\ $$ Commented by MJS last…