Answer:
[tex]0.0004[/tex]
Step-by-step explanation:
To start off, find out the probability that if you chose a number at random, you would pick a certain number. To do this count how many numbers you have, in this case it's 10. So if each of the numbers had the same chance to be picked, the probability of picking a certain number is [tex]\frac{1}{10}[/tex].
The same thing goes for the letters. Count how many you have, in this case it's the whole alphabet, so, 26 letters. Therefore, the probability of picking a certain letter is [tex]\frac{1}{26}[/tex].
Now for how we can use these probabilities. We want the probability that the code is a 7 AND a 4 AND a M. Because we are using AND and not OR, we should use the multiplication rule which is: [tex]P(Aand B) = P(A)[/tex] × [tex]P(B)[/tex].
Using this rule we can do the calculation: [tex]P(AandBandC) = P(A)[/tex] × [tex]P(B)[/tex] ×[tex]P(C)[/tex]
In this case, [tex]P(A) =\frac{1}{10}[/tex] , [tex]P(B) =\frac{1}{10}[/tex] and [tex]P(C) = \frac{1}{26}[/tex].
[tex]\frac{1}{10}[/tex] × [tex]\frac{1}{10}[/tex] × [tex]\frac{1}{26}[/tex] [tex]= 0.0003846...[/tex]
We can round this to [tex]0.0004[/tex]
