A Psychologist Conducts an Experiment in Which a Mouse Is

Multiple Choice

A psychologist conducts an experiment in which a mouse is placed in a T-maze, where it has a choice at the T-junction of turning left and receiving a reward (cheese) or turning right and receiving a mild shock. At the end of each trial a record is kept of the mouse's response. It is observed that the mouse is as likely to turn left (state 1) as right (state 2) during the first trial. In subsequent trials, however, the observation is made that if the mouse had turned left in the previous trial, then the probability that it will turn left in the next trial is .6, whereas the probability that it will turn right is .4. If the mouse had turned right in the previous trial, then the probability that it will turn right in the next trial is .2, whereas the probability that it will turn left is .8. In the long run, what percentage of the time will the mouse turn left at the T-junction? Please round the answer to one decimal place. ​

A) 23.2%
B) 66.7%
C) 93.0%
D) 50.4%