Question Number 112572 by Aina Samuel Temidayo last updated on 08/Sep/20
Commented by mr W last updated on 08/Sep/20
$${see}\:{Q}\mathrm{112533} \\ $$
Answered by mr W last updated on 09/Sep/20
$$\mathrm{1}\:\&\:\mathrm{11} \\ $$$$\left….\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\right\}\:\mathrm{10}\:{pairs} \\ $$$$\mathrm{10}\:\&\:\mathrm{20} \\ $$$$ \\ $$$$\mathrm{21}\:\&\:\mathrm{31} \\ $$$$\left….\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\right\}\:\mathrm{10}\:{pairs} \\ $$$$\mathrm{30}\:\&\:\mathrm{40} \\ $$$$ \\ $$$$…… \\ $$$$ \\ $$$$\mathrm{81}\:\&\:\mathrm{91} \\ $$$$\left….\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\right\}\:\mathrm{10}\:{pairs} \\ $$$$\mathrm{90}\:\&\:\mathrm{100} \\ $$$$ \\ $$$${i}.{e}.\:{we}\:{can}\:{select}\:{at}\:{most}\:\mathrm{50}\:{numbers} \\ $$$${without}\:{two}\:{numbers}\:{among}\:{them} \\ $$$${whose}\:{difference}\:{is}\:\mathrm{10}. \\ $$$$ \\ $$$$\Rightarrow{the}\:{answer}\:{is}\:\mathrm{51}. \\ $$
Commented by Aina Samuel Temidayo last updated on 09/Sep/20
$$\mathrm{Thanks}. \\ $$