Question

Fie multimea M = { x ∈ N | x ≤ 7 si x > 3 } . Determinati cardinalul multimii M . 

Answer 1

M = { 4, 5. 6, 7 }   -   4 nr., deci Card M = 4

Answer 2

$x>3 \ \ \ \ \And \ \ \ \ x \leq 7 \\\\ x= \{4;5;6;7\} \\\\ \boxed{Card \ M=4}$