Răspuns: 12 numere
Explicație pas cu pas:
Fie [tex] \large\bf\overline{abc}[/tex]numerele de trei cifre
[tex] \large\bf a, b, c \in \{1,2,5,7,8,9 \}[/tex]
[tex] \large\bf c \in \{2,8\}[/tex]
[tex]\large\bf 200> \overline{abc}> 700\implies a\in\{2,5\}[/tex]
[tex]\large\bf \overline{2b8} \in \{218,258,278,298\}[/tex]
[tex]\large\bf \overline{5b2} \in \{512, 572,582,592\}[/tex]
[tex]\large\bf \overline{5b8} \in \{518, 528,578,598\}[/tex]
[tex]\color {cc0000}\Large\bf \overline{abc} \in \{512,518,572,578,582,528,592,598, 218,258,278,298\}[/tex]
[tex]\large \boxed {\bf 12\:numere\:respecta\:conditiile\:problemei}[/tex]
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