this will generate numbers between 250 and 499 because of the behaviors of rand and int:

rand Returns a random fractional number greater than or equal to 0 and less than the value of EXPR.

int Returns the integer portion of EXPR. If EXPR is omitted, uses $_. You should not use this function for rounding: one because it trun-cates towards 0, and two because machine representations of floating point numbers can sometimes produce counterintuitive results.

rand(250) will always return a number less than 250 and int will never round up.

use rand(251)