MCQ
The product of $r$ consecutive positive integers is divisible by:
- ✓$r!$
- B$(r − 1)!$
- C$(r + 1)!$
- DNone of these
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$A=\left\{(x, y) \in R \times R \mid 2 x^{2}+2 y^{2}-2 x-2 y=1\right\}$
$B=\left\{(x, y) \in R \times R \mid 4 x^{2}+4 y^{2}-16 y+7=0\right\} \text { and }$
$C=\left\{(x, y) \in R \times R \mid x^{2}+y^{2}-4 x-2 y+5 \leq r^{2}\right\}$
Then the minimum value of $|r|$ such that $A \cup B \subseteq C$ is equal to: