10. credit cards place a three - digit security code on the back of cards. what is the probability that a…

10. credit cards place a three - digit security code on the back of cards. what is the probability that a code starts with the number 7?

10. credit cards place a three - digit security code on the back of cards. what is the probability that a code starts with the number 7?

Answer

Explanation:

Step1: Determine total possibilities for first - digit

Each digit of the security code can be any number from 0 - 9. So, there are 10 possible numbers for the first digit of the three - digit code.

Step2: Determine favorable possibilities for first - digit

We want the first digit to be 7, and there is only 1 way for the first digit to be 7.

Step3: Calculate probability

The probability $P$ of an event is given by the formula $P=\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$. Here, the number of favorable outcomes for the first digit is 1 and the total number of outcomes for the first digit is 10. So, $P = \frac{1}{10}$.

Answer:

$\frac{1}{10}$