Question

Fie multimea A={x∈ℕ| √24 < x < √256}.Probabilitatea ca, alegand un numar din multimea A,acesta sa fie prim este.... ?
Help me please :D

Answer 1

$A=\{x \in N / \sqrt{24}\ \textless \ x\ \textless \ \sqrt{256} \} \\\\ 4,.. \ \textless \ x\ \textless \ 16 \\ x \in N \\\\ \Longrightarrow A = \{5;6;7;8;9;10;11;12;13;14;15\} \\\\\\ P=\frac{nr. \ cazurilor \ favorabile}{nr. \ cazurilor \ posibile } \\\\ \hbox{Nr. prime din multimea A sunt \to 5;7;11;13 ... \hbox{(4 nr. in total)}}$

$\hbox{Multimea A are in total 11 nr.} \\\\\\\boxed{P=\frac{4}{11}}$