Tanya is training a turtle for a turtle race. For every 2/3 of an hour that the turtle is crawling, he can travel 3/25 of a mile. At what unit rate is the turtle crawling?
If the turtle can travel 3/25 of a mile in 2/3 of an hour, then it can travel [(3/25)/(2/3)] = 3/25 * 3/2 = 9/50 of a mile in 1 hour.
Therefore, the turtle is crawling at a unit rate of 9/50 mile per hour. Answer: \boxed{\frac{9}{50}}.