A bookseller has two display windows. She plans to display 3 new fiction books in the left window, and 3 new non-fiction books in the right window. Assuming she can put the four fiction books in any order, and separately, the three non-fiction books in any order, how many total configurations will there be for the two display windows?  Choose the correct choice:  A) 24  B) 72  C) 144  D) 36  E) 420
The left window will have permutations of the 3 fiction books, so the number of possibilities for that window is   permutations = 3! = (3)(2)(1) = 6   The right window will have permutations of the 3 non-fiction books, so the number of possibilities for that window is   permutations = 3! = (3)(2)(1) = 6   Any of the 24 displays of the left window could be combined with any of the 6 displays of the right window, so the total number of configurations is 6*6= 
<gadget id="calculator">6*6</gadget>
<output>36</output>
36   Answer: 36.
<result>D</result>
A bookseller has two display windows. She plans to display 3 new fiction books in the left window, and 3 new non-fiction books in the right window. Assuming she can put the four fiction books in any order, and separately, the three non-fiction books in any order, how many total configurations will there be for the two display windows?