SOLUTION: On a shelf there are four mathematic books and eight english books. if the books are to be arranged so that the mathematics books are together, in how many ways can this be done?
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Question 4230: On a shelf there are four mathematic books and eight english books. if the books are to be arranged so that the mathematics books are together, in how many ways can this be done? Answer by ichudov(507) (Show Source):
You can put this solution on YOUR website! four mathematics books can be arranged in 4! (four FACTORIAL) ways. The engligh books can be arranged in 8! ways. Then the math books can be inserted (all together) into english books in 9 different ways (to the left of all english books, after first, after second, ..., after 8th -- 9 possibilities). That makes 9*4!*8! possibilities.
