Question

Help

Answer 1

@mathmale

Answer 2

@confluxepic

Answer 3

i'd say C

Answer 4

@ParthKohli

Answer 5

How many numbers that do not have zero at all? Let's answer that below:
Suppose we have three blanks. Each blank can be filled with digits 1 to 9 (we're not gonna count zero!). So overall, we have \(9 \cdot 9 \cdot 9 = 729\) of these numbers. And from 100 to 999, there are \(900\) numbers. So the probability is:\[P(\text{at least one zero}) = 1 - P(\text{no zero}) = 1 - \frac{729}{900} \]