Metode, kas pierāda izteiksmju vienādību, pamatojot, ka to var saskaitīt divos veidos.
Some of \(273\) villagers always tell the truth, the remaining ones lie all the time. Each of the villagers has exactly one favourite day of the week. There was a poll of all the villagers, and they were asked to answer seven questions with either "Yes" or "No":
Question | ||
---|---|---|
Is Monday your favorite day? | \(\square\) Yes | \(\square\) No |
Is Tuesday your favorite day? | \(\square\) Yes | \(\square\) No |
Is Wednesday your favorite day? | \(\square\) Yes | \(\square\) No |
Is Thursday your favorite day? | \(\square\) Yes | \(\square\) No |
Is Friday your favorite day? | \(\square\) Yes | \(\square\) No |
Is Saturday your favorite day? | \(\square\) Yes | \(\square\) No |
Is Sunday your favorite day? | \(\square\) Yes | \(\square\) No |
The number of "Yes" answers received to each question was as follows: Monday - \(51\), Tuesday - \(52\), Wednesday - \(53\), Thursday - \(55\), Friday - \(54\), Saturday - \(56\), Sunday - \(57\). How many villagers lie all the time?
Daži no 273 ciema iedzīvotājiem visu laiku saka patiesību,
pārējie visu laiku melo. Katram no ciema iedzīvotājiem
ir tieši viena mīļākā nedēļas diena. Aptaujājot iedzīvotājus,
viņiem tika lūgts atbildēt uz septiņiem jautājumiem,
katrā no tiem izvēloties vienu no dotajām atbildēm:
Uz katru jautājumu saņemto apstiprinošo ("jā") atbilžu skaits bija šāds:
pirmdiena – \(51\), otrdiena – \(52\),
trešdiena – \(53\), ceturtdiena – \(54\), piektdiena – \(55\),
sestdiena – \(56\), svētdiena – \(57\). Cik ciema iedzīvotāji visu laiku melo?
Kvadrāts sastāv no \(4 \times 4\) rūtiņām. Vai var tajās ierakstīt naturālus skaitļus no \(1\) līdz \(16\) (katrā rūtiņā - citu skaitli) tā, lai skaitļu summas visās rindās un kolonnās būtu dažādas un visas dalītos ar (A) \(4\), (B) \(8\)?