Question Number 211311 by a.lgnaoui last updated on 05/Sep/24
$$\boldsymbol{\mathrm{Dterminer}}\:\boldsymbol{\mathrm{le}}\:\boldsymbol{\mathrm{nombre}}\:\boldsymbol{\mathrm{total}}\:\:\boldsymbol{\mathrm{des}}\:\boldsymbol{\mathrm{nombres}}\: \\ $$$$\boldsymbol{\mathrm{de}}\:\left(\mathrm{3}\:\boldsymbol{\mathrm{chiffres}}\right)\boldsymbol{\mathrm{qui}}\:\boldsymbol{\mathrm{sont}}\:\boldsymbol{\mathrm{impair}}\left(\:\boldsymbol{\mathrm{et}}\right)\:\boldsymbol{\mathrm{divisibles}}\: \\ $$$$\boldsymbol{\mathrm{par}}\:\mathrm{9}\:\:\:\boldsymbol{\mathrm{compris}}\:\boldsymbol{\mathrm{entre}}\:\mathrm{100}\:\boldsymbol{\mathrm{et}}\:\mathrm{500}.? \\ $$$$\boldsymbol{\mathrm{formule}}\:\boldsymbol{\mathrm{si}}\:\boldsymbol{\mathrm{c}}\:\boldsymbol{\mathrm{est}}\:\boldsymbol{\mathrm{possible}}? \\ $$$$ \\ $$
Answered by mr W last updated on 05/Sep/24
$${the}\:{first}\:{one}\:{is}\:\mathrm{117},\:{the}\:{second}\:{one} \\ $$$${is}\:\mathrm{117}+\mathrm{18},\:{the}\:{third}\:{one}\:{is}\:\mathrm{117}+\mathrm{18}+\mathrm{18}, \\ $$$${etc}.\: \\ $$$${generally}: \\ $$$${N}=\mathrm{117}+\mathrm{18}{k} \\ $$$${N}<\mathrm{500}\:\Rightarrow{k}\leqslant\mathrm{21} \\ $$$$\Rightarrow\mathrm{0}\leqslant{k}\leqslant\mathrm{21}\:\Rightarrow\mathrm{22}\:{such}\:{numbers} \\ $$
Commented by a.lgnaoui last updated on 05/Sep/24
$$\mathrm{thank}\:\mathrm{you}\:\mathrm{very}\:\mathrm{much}. \\ $$