Category: Arithmetic

Question Number 8846 by Rasheed Soomro last updated on 31/Oct/16 $$\mathrm{Let}\mathrm{by}({\mathrm{a}}_1,{\mathrm{a}}_2,\dots {\mathrm{a}}_{\mathrm{n}})\mathrm{we}\mathrm{mean}\mathrm{LCM}$$$$\mathrm{of}{\mathrm{a}}_1,{\mathrm{a}}_2,\dots {\mathrm{a}}_{\mathrm{n}},\mathrm{where}{\mathrm{a}}_{\mathrm{i}}\in \mathbb{N}.$$$$\mathrm{Prove}\mathrm{or}\mathrm{disprove}\mathrm{that}((\mathrm{a},\mathrm{b}),(\mathrm{b},\mathrm{c}))=(\mathrm{a},\mathrm{b},\mathrm{c}).$$ Answered…

Question Number 8829 by tawakalitu last updated on 30/Oct/16 $$\mathrm{The}\mathrm{LCM}\mathrm{of}\mathrm{three}\mathrm{whole}\mathrm{number}\mathrm{is}144.$$$$\mathrm{what}\mathrm{is}\mathrm{their}\mathrm{third}\mathrm{common}\mathrm{multiple}.$$ Commented by Rasheed Soomro last updated on 31/Oct/16 $$\mathrm{All}\mathrm{the}\mathrm{common}\mathrm{multiples}\mathrm{are}\mathrm{multiples}\mathrm{of}\mathrm{LCM}.$$$$\mathrm{First}\:\mathrm{common}\:\mathrm{multiple}\:\mathrm{is}\:\mathrm{LCM}\:\mathrm{itself}.\:\mathrm{The}\:\mathrm{second}…

Question Number 8764 by tawakalitu last updated on 26/Oct/16 $$\left(\mathrm{a}\right)\mathrm{Find}\mathrm{the}\mathrm{sum}\mathrm{given}\mathrm{by}$$$${\mathrm{S}}_{\mathrm{n}}=\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+\dots +\frac{1}{(2\mathrm{n}-1)(2\mathrm{n}+1)}$$$$\left(\mathrm{b}\right)\mathrm{find}\mathrm{the}\mathrm{limit}\mathrm{of}{\mathrm{S}}_{\mathrm{n}}\mathrm{as}\mathrm{n}\to \mathrm{\infty }$$ Commented by sou1618 last updated on 26/Oct/16…

Question Number 139771 by Engr_Jidda last updated on 01/May/21 Commented by mohammad17 last updated on 01/May/21 $$yessirrealyimsorycanyousolvethis?$$ Commented by mr W last updated…

Question Number 8558 by Sopheak last updated on 16/Oct/16 Commented by FilupSmith last updated on 16/Oct/16 $$S_n=\underset{k=1}{\sum ^n}\frac{k^4}{(2k-1)(2k+1)}$$$$\frac{1}{(2k-1)(2k+1)}=\frac{A}{2k-1}+\frac{B}{2k+1}$$$$\mathrm{1}={A}\left(\mathrm{2}{k}+\mathrm{1}\right)+{B}\left(\mathrm{2}{k}−\mathrm{1}\right)…