Question Number 198851 by Tawa11 last updated on 25/Oct/23 You want to arrange 17 books on the shelf of a bookstore. The shelf is dedicated…
Question Number 198809 by dimentri last updated on 24/Oct/23 $$\:\:\:\:\:{sum}\:{of}\:{roots}\: \\ $$$$\:\mathrm{log}\:_{\mathrm{3}} {x}\:+\:\mathrm{log}\:_{\mathrm{3}} \left(\mathrm{2},\mathrm{5}\right)\:+\:\mathrm{log}\:_{{x}} \mathrm{9}\:=\:\mathrm{3}+\:\mathrm{log}\:_{{x}} \mathrm{5}\: \\ $$ Answered by a.lgnaoui last updated on 24/Oct/23…
Question Number 198576 by mr W last updated on 22/Oct/23 How many numbers with a maximum of 5 digits, greater than 4000, can be formed…
Question Number 198548 by HomeAlone last updated on 21/Oct/23 $${return}\mathrm{return}\left(\right) \\ $$$$\mathrm{p}<\mathrm{1} \\ $$$$\mathrm{p} \\ $$$$\mathrm{2} \\ $$$$\mathrm{3} \\ $$$$\mathrm{4} \\ $$$$\mathrm{5} \\ $$$$\mathrm{6} \\…
Question Number 198283 by cortano12 last updated on 16/Oct/23 $$\mathrm{Given}\:\mathrm{the}\:\mathrm{number}\:\mathrm{of}\:\:\mathrm{consisting} \\ $$$$\:\mathrm{of}\:\mathrm{4}\:\mathrm{digits}\:\mathrm{abcd}\:\mathrm{such}\:\mathrm{that}\: \\ $$$$\:\mathrm{a}\leqslant\mathrm{b}\leqslant\mathrm{c}\leqslant\mathrm{d}\:\mathrm{is}\:… \\ $$$$\:\left(\mathrm{A}\right)\:\mathrm{495}\:\:\:\left(\mathrm{B}\right)\:\mathrm{385}\:\:\:\:\:\left(\mathrm{C}\right)\:\mathrm{275} \\ $$$$\:\left(\mathrm{D}\right)\:\mathrm{165}\:\:\:\:\left(\mathrm{E}\right)\:\mathrm{55}\: \\ $$ Commented by mr W last…
Question Number 198242 by Tawa11 last updated on 15/Oct/23 How many numbers with a maximum of 5 digits, greater than 4000, can be formed with…
Question Number 198231 by pticantor last updated on 14/Oct/23 Answered by witcher3 last updated on 14/Oct/23 $$\mathrm{C}_{\mathrm{n}} ^{\mathrm{p}} =\frac{\mathrm{n}!}{\mathrm{p}!.\left(\mathrm{n}−\mathrm{p}\right)!} \\ $$$$\mathrm{pC}_{\mathrm{n}} ^{\mathrm{p}} =\frac{\mathrm{n}!}{\left(\mathrm{p}−\mathrm{1}\right)!.\left(\mathrm{n}−\mathrm{p}\right)!}=\mathrm{n}.\frac{\left(\mathrm{n}−\mathrm{1}\right)!}{\left(\mathrm{p}−\mathrm{1}\right)!.\left(\mathrm{n}−\mathrm{1}−\left(\mathrm{p}−\mathrm{1}\right)\right)!} \\ $$$$=\mathrm{nC}_{\mathrm{n}−\mathrm{1}}…
Question Number 198022 by cortano12 last updated on 08/Oct/23 $$\:\:\mathrm{Five}\:\mathrm{letters}\:\mathrm{are}\:\mathrm{selected}\:\mathrm{from} \\ $$ Answered by mr W last updated on 08/Oct/23 $${OOOXX}\:\:\Rightarrow\mathrm{2} \\ $$$${OOOXY}\:\:\Rightarrow\mathrm{2}×{C}_{\mathrm{2}} ^{\mathrm{4}} =\mathrm{12}…
Question Number 197589 by mr W last updated on 23/Sep/23 $${how}\:{many}\:{natural}\:{numbers}\:{with}\:\mathrm{4} \\ $$$${different}\:{digits}\:{are}\:{divisible}\:{by}\:\mathrm{3}? \\ $$ Answered by mr W last updated on 24/Sep/23 $${A}=\left\{\mathrm{1},\mathrm{4},\mathrm{7}\right\} \\…
Question Number 197578 by mr W last updated on 22/Sep/23 Commented by mr W last updated on 22/Sep/23 $${unsolved}\:{old}\:{question}\:{Q}#\mathrm{196915} \\ $$ Answered by mr W…