Which city's subway has a length that is a prime number of miles?
New York, U.S. = 247
Mexico City, Mexico = 111
Paris, France = 125
Moscow, Russia = 152
Seoul, South Korea = 83
Tokyo, Japan = 105
http://www.mathsisfun.com/prime_numbers.html
Seoul,South Korea
247
To determine which city's subway has a length that is a prime number of miles, we can check if each subway length is a prime number.
A prime number is a number greater than 1 that has no divisors other than 1 and itself. We can use this definition to check if a number is prime.
Let's check each subway length:
- New York, U.S. = 247: 247 is not a prime number as it is divisible by 1, 13, 19, and 247 itself.
- Mexico City, Mexico = 111: 111 is not a prime number as it is divisible by 1, 3, 37, and 111 itself.
- Paris, France = 125: 125 is not a prime number as it is divisible by 1, 5, 25, and 125 itself.
- Moscow, Russia = 152: 152 is not a prime number as it is divisible by 1, 2, 4, 8, 19, 38, 76, and 152 itself.
- Seoul, South Korea = 83: 83 is a prime number as it is only divisible by 1 and 83.
- Tokyo, Japan = 105: 105 is not a prime number as it is divisible by 1, 3, 5, 7, 15, 21, 35, and 105 itself.
Hence, the subway in Seoul, South Korea has a length that is a prime number of miles.