A bookseller has two display windows. She plans to display 4 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 from the following answers:
A) 24
B) 72
C) 144
D) 336
E) 420
Explanations   1) The left window will have permutations of the 4 fiction books, so the number of possibilities for that window is   permutations = 4! = (4)(3)(2)(1) = 24   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 24*6= 
<gadget id="calculator">24*6</gadget>
<output>144</output>
144   Answer: 144.
<result>C</result>
A bookseller has two display windows. She plans to display 4 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?