Complete Question:
Yanay gets a lot of spam calls. An area code is defined to be a three digit number from 200-999 inclusive. In reality, many of these area codes are not in use, but for this question we'll simplify things and assume they all are.
Assuming each area code is just as likely as any other, what's the probability that the area code of two back to back spam calls are 804?
Answer:
1/6400 or 0.0000015625
Step-by-step explanation:
Given
Area Codes = 200 to 999 (inclusive)
Required
Determine the probability that back to back calls have area code 804
[First, we need to calculate the totality of area codes]
Total Area Codes = 999 - 200 + 1
Total Area Codes = 800
The probability of each code is 1/800
So, the probability of having back to back code of 804 is:
Probability = 1/800 * 1/800
Probability = (1/800)²
Probability = 1/640000
Hence, the required probability is 1/640000 or 0.0000015625
