document.write( "Question 848552: There are three teachers and eight students on the student council. How many ways can a committee of 4 people be chosen if there must be at least one teacher on it? \n" ); document.write( "
Algebra.Com's Answer #511161 by swincher4391(1107)![]() ![]() You can put this solution on YOUR website! This can be achieved by:\r \n" ); document.write( "\n" ); document.write( "(3 students, 1 teacher) (2 students, 2 teachers) (1 student, 3 teachers)\r \n" ); document.write( "\n" ); document.write( "(8 choose 3)(3 choose 1) + (8 choose 2)(3 choose 2) + (8 choose 1)(3 choose 3) = 260\r \n" ); document.write( "\n" ); document.write( "Alternative method. There are (11 choose 4) total ways to order. The only scenario left out is [4 students, 0 teachers] (note we cannot have 0 students, 4 teachers).\r \n" ); document.write( "\n" ); document.write( "So (11 choose 4) - (8 choose 4)(3 choose 0) = 260 \n" ); document.write( " |