The total number of 16-digit numbers we can form with the digits 0, 1, ...9 , with
0 allowed to be the first digit, is [tex]10^{16} [/tex]
because any of the 16 digits can be one of {0, 1, 2, ...9}, and can be combined with the 15 others, each of which have also 10 possibilities.
100 million is [tex]100*10^{6}=10^{8} [/tex]
P (selecting valid)=n(valid)/ n(all) = [tex] \frac{10^{8}}{10^{16}}= \frac{1}{10^{8}}=0.00000001[/tex]
Answer: 0.00000001
