# Probability

How probable is a randomly selected three-digit number divisible by five or seven?

Result

p =  42.778 %

#### Solution:

$a=385 \ \\ b=999-100+1=900 \ \\ p=100 \cdot \ \dfrac{ a }{ b }=100 \cdot \ \dfrac{ 385 }{ 900 } \doteq \dfrac{ 385 }{ 9 } \doteq 42.7778 \doteq 42.778 \%$

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