document.write( "Question 218176: Kindly answer this question please!!! Thanks!! In how many ways 4 people be seated in a row of 6 chairs if A.they can be seated anywhere B. the empty chairs are adjacent to each other? \n" ); document.write( "
Algebra.Com's Answer #164339 by Theo(13342)![]() ![]() You can put this solution on YOUR website! 4 people 6 chairs \n" ); document.write( "----- \n" ); document.write( "sitting anywhere, the number is 15. \n" ); document.write( "if the empty chairs have to be adjacent, the number is 5 \n" ); document.write( "----- \n" ); document.write( "let's do adjacent first. \n" ); document.write( "you have 6 chairs and 4 people. \n" ); document.write( "that means 2 empty chairs. \n" ); document.write( "if they have to be together, they become equivalent to 1 empty chair with the total number of chairs being 5. \n" ); document.write( "you now have 5 chairs and one of them has to be empty. \n" ); document.write( "this can happen in 5 ways. \n" ); document.write( "you get: \n" ); document.write( "effff \n" ); document.write( "fefff \n" ); document.write( "ffeff \n" ); document.write( "fffef \n" ); document.write( "ffffe \n" ); document.write( "----- \n" ); document.write( "no other combination is possible. \n" ); document.write( "----- \n" ); document.write( "general formula for number of combinations is: \n" ); document.write( "n! / ((x)!*(n-x)!) \n" ); document.write( "formula for this problem is 5! / (1!*4!) \n" ); document.write( "where: \n" ); document.write( "1! represents x! \n" ); document.write( "4! represents (n-x)! \n" ); document.write( "----- \n" ); document.write( "the first part of your problem is solved as follows: \n" ); document.write( "you have 6 slots. \n" ); document.write( "you can fill them with 4 people \n" ); document.write( "that will leave 2 empty slots. \n" ); document.write( "----- \n" ); document.write( "the general formula for number of possible combinations of 4 out of 6 is once again n! / ((x)!*(n-x)!) \n" ); document.write( "This becomes 6! / (2!*4!) \n" ); document.write( "where: \n" ); document.write( "n = 6 \n" ); document.write( "x = 2 \n" ); document.write( "n-x = 4 \n" ); document.write( "----- \n" ); document.write( "The answer is 6*5*4*3*2*1 / 2*1*4*3*2*1 30/2 = 15 \n" ); document.write( "----- \n" ); document.write( "there are 15 combinations possible. \n" ); document.write( "They are: \n" ); document.write( "eeffff \n" ); document.write( "efefff \n" ); document.write( "effeff \n" ); document.write( "efffef \n" ); document.write( "effffe \n" ); document.write( "feefff \n" ); document.write( "fefeff \n" ); document.write( "feffef \n" ); document.write( "fefffe \n" ); document.write( "ffeeff \n" ); document.write( "ffefef \n" ); document.write( "ffeffe \n" ); document.write( "fffeef \n" ); document.write( "fffefe \n" ); document.write( "ffffee \n" ); document.write( "----- \n" ); document.write( "You have 15 ways in which you can fill the 6 seats with 4 people assuming they can sit anywhere they want. \n" ); document.write( "----- \n" ); document.write( "You have 5 ways in which you can fill the 6 seats with 4 people assuming the empty seats have to be together. \n" ); document.write( "-----\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |