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. Throughout these questions, you should assume that Yanay’s area code is 781.
The correct answer and explanation is:
The total number of valid area codes, based on the range from 200 to 999 inclusive, is:
Answer: 800
Explanation:
An area code is a three-digit number used to identify a specific geographic region for phone calls. According to the simplified rules in this question, valid area codes range from 200 to 999. To determine how many possible area codes exist within this range, subtract the smallest valid code from the largest and then add 1 to account for both endpoints: 999−200+1=800999 – 200 + 1 = 800
So, there are 800 possible area codes.
Although not all these area codes are actually used in real-life telecommunication systems, for the purpose of this question it is assumed that every number in this range is a valid and active area code. This assumption simplifies calculations by ignoring reserved or unassigned codes.
Yanay’s area code is specifically given as 781, which falls within the valid range. This detail might be important for follow-up questions, such as calculating probabilities or identifying calls from outside his area.
Understanding this range is essential in analyzing how likely it is for someone like Yanay to receive calls from different area codes, including those that might be associated with spam. If spam calls originate from random area codes across the full range, each code (such as 781) would theoretically have a 1 in 800 chance of being used by a spam caller, assuming equal probability.
In reality, spammers might spoof numbers with local area codes to increase the chances of the recipient answering, but that complexity is not part of this problem. The key point here is that under the assumption given, the total number of valid area codes is 800.