Chapter 13.8, Problem 14PPS

To determine

To find: The probability that last two digits in social security number are someone`s age.

Answer to Problem 14PPS

The required probability of last two digits being someone`s age is $0.01$ .

Explanation of Solution

Given information:

First three digits in social security number are a geographic code. The next two digits are determined by the year and state, where number is issued. And last four digits are random numbers

Concept/Formula used: Probability of an event is calculated using the following formula,

  $\text{Probability}=\frac{\text{Total favorable cases }}{\text{Total number of cases}}$

Calculation: As at a particular time, someone`s age is a single number, so total favorable cases are 1. Also, last two digits may by any from 00 to 99 i.e. total 100 such two digits numbers are possible, out of those, any such combination of two digits, may be someone`s age. So, total number of cases are 100.

So, required probability of being last two digits, someone`s age

  $=\frac{1}{100}=0.01$

Conclusion: So, the required probability of being last two digits, someone`s age is $0.01$ .