Question Number 115902 by bemath last updated on 29/Sep/20
$${The}\:{secret}\:{number}\:{is}\:{made}\:{from} \\ $$$${the}\:{numbers}\:\mathrm{1},\mathrm{2},\mathrm{2},\mathrm{3},\mathrm{3},\mathrm{4},\mathrm{5}.\: \\ $$$${Many}\:{secret}\:{numbers}\:{can}\:{be}\:{created} \\ $$$${if}\:{the}\:{same}\:{number}\:{is}\:{not}\:{adjacent} \\ $$$${except}\:{in}\:{the}\:{first}\:{two}\:{place}\:{is}\:\_ \\ $$$$\left({a}\right)\mathrm{1142}\:\:\:\:\left({b}\right)\:\mathrm{1212}\:\:\:\:\left({c}\right)\:\mathrm{1246} \\ $$$$\left({d}\right)\:\mathrm{1248}\:\:\:\left({e}\right)\:\mathrm{1250} \\ $$