document.write( "Question 361410: In a class of 50 students, 31 are democrats, 13 are business majors, and 3 of the business majors are democrats. If one student is randomly selected from the class, find the probability of choosing a Democrat or business major. \n" ); document.write( "
Algebra.Com's Answer #257702 by neatmath(302)![]() ![]() You can put this solution on YOUR website! There are 50 students total. \r \n" ); document.write( "\n" ); document.write( "Now we need to find out how many students fit our parameters of Democrat or business major. \r \n" ); document.write( "\n" ); document.write( "There are 31 Democrats, and 13 business majors. However, 3 of the business majors are ALSO Democrats. \r \n" ); document.write( "\n" ); document.write( "So here are the totals we really have for Democrats and business majors: \r \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( "\n" ); document.write( "Thus, the probability of choosing a Democrat or business major is just: \r \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( "\n" ); document.write( "0.82 \r \n" ); document.write( "\n" ); document.write( "Therefore, P(Democrat or business major)=0.82 \r \n" ); document.write( "\n" ); document.write( "We could also use the formula P(A or B) = P(A) + P(B) - P(A and B) to calculate this. \r \n" ); document.write( "\n" ); document.write( "This is likely how your instructor would like you to solve this problem, see below: \r \n" ); document.write( "\n" ); document.write( "P(D or B)=P(D)+P(B)-P(D and B) \r \n" ); document.write( "\n" ); document.write( "P(D or B)=31/50+13/50-3/50 \r \n" ); document.write( "\n" ); document.write( "P(D or B)=41/50=0.82 which agrees with our probability above! \r \n" ); document.write( "\n" ); document.write( "I hope this helps! \n" ); document.write( " |