Prime Numbers A prime number is a number that is evenly divisible only by 1 and itself. The prime numbers less than 100 are listed below.
$$
\begin{array}{lllllllllll}{2} & {3} & {5} & {7} & {11} & {13} & {17} & {19} & {23} & {29} & {31} \\ {37} & {41} & {43} & {47} & {53} & {59} & {61} & {67} & {71} & {73} & {79} \\ {83} & {89} & {97} & {} & {} & {} & {} & {}\end{array}
$$
Choose one of these numbers at random. Find the probability that
a. The number is odd
b. The sum of the digits is odd
c. The number is greater than 70