Category: Arithmetic

Question Number 88207 by MAB last updated on 09/Apr/20 $$whatisthebiggestprimepverifying:$$$$p=\underset{k=1}{\sum ^n}\left[\sqrt{k}\right]$$$$wheren\in \mathbb{N}\mathrm{and}\left[x\right]isfloor\left(x\right)$$ Commented by MJS last updated on 09/Apr/20…

Question Number 153565 by talminator2856791 last updated on 08/Sep/21 $$$$$$\mathrm{define}d\left(n\right)\mathrm{to}\mathrm{be}\mathrm{the}\mathrm{sum}\mathrm{of}\mathrm{the}\mathrm{digits}$$$$\mathrm{of}n.$$$$\mathrm{i}.\mathrm{e}d\left(1000\right)=1,d\left(999\right)=27$$$$$$$$\mathrm{find}d\left(d\left(d\left(d\left(d\left(5^{{10}^{100}}\right)\right)\right)\right)\right)$$$$\: \…

Question Number 87935 by Ar Brandon last updated on 07/Apr/20 $$Amanbuysahenat9\mathrm{\$}andsellsitat11\mathrm{\$}.Hebuys$$$$thesamehenlateronat12\mathrm{\$}andsellsitnow$$$$at14\mathrm{\$}.Whatishistotalbenefit?$$ Answered by MJS last updated on 07/Apr/20 $$\mathrm{0}−\mathrm{9}+\mathrm{11}−\mathrm{12}+\mathrm{14}=\mathrm{4}…

Question Number 87918 by M±th+et£s last updated on 07/Apr/20 Commented by M±th+et£s last updated on 07/Apr/20 $$prove$$ Terms of Service Privacy Policy Contact:…

Question Number 22345 by ibraheem160 last updated on 16/Oct/17 $$6^{\mathrm{x}+2}=2\left(3^{\mathrm{x}}\right),\mathrm{find}\mathrm{x}?$$ Commented by JI Siam last updated on 21/Dec/17 $$\mathrm{Here}\:\mathrm{6}^{\mathrm{x}+\mathrm{1}} =\mathrm{3}^{\mathrm{x}−\mathrm{1}} \:\mathrm{so},\mathrm{likely}\:\mathrm{x}\:\mathrm{is}\:\mathrm{not}\:\mathrm{a}\:\mathrm{normal}\:\mathrm{number}.…