Final answer:
The probability of completing the puzzle between 7 to 9 minutes, when it is uniformly distributed between 6 and 10 minutes, is calculated as 0.5. This falls under the subject of Mathematics for High School.
Step-by-step explanation:
The question asks for the probability of completing a puzzle between 7 to 9 minutes when the time to finish is uniformly distributed between 6 and 10 minutes. To find this probability, we divide the interval of interest (7 to 9 minutes) by the total time interval (6 to 10 minutes).
The total time interval is 10 - 6 = 4 minutes. The interval of interest from 7 to 9 minutes is 9 - 7 = 2 minutes. The probability is then calculated as:
P(7 < X < 9) = (Interval of interest) / (Total interval) = 2 / 4 = 0.5
Therefore, the probability of completing the puzzle between 7 to 9 minutes is 0.5, which corresponds to option a.