Niki holds two part-time jobs, Job I and Job II. She never wants to work more than a total of 12 hours a week. She has determined that for every hour she works at Job I, she needs 2 hours of preparation time, and for every hour she works at Job II, she needs one hour of preparation time, and she cannot spend more than 16 hours for preparation. She makes $40 an hour at Job I, and $30 an hour at Job II and wants to maximize her income. Using simplex method, what is the smallest number in the bottom row of the simplex table?