document.write( "Question 1117797: Please help me with this question:
\n" );
document.write( "The door prizes at a dance are gift certificates from local merchants. There are four $10 certificates, five $20 certificates, and three $50 certificates. The prize envelopes are mixed together in a bag and are drawn at random.\r
\n" );
document.write( "\n" );
document.write( "Determine the probability distribution for the number of $20 certificates in the first two prizes drawn. \n" );
document.write( "
Algebra.Com's Answer #732934 by Theo(13342)![]() ![]() You can put this solution on YOUR website! you have:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "4 ten dollar certificates \n" ); document.write( "5 twenty dollar certificates \n" ); document.write( "3 fifty dollar certificates.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's a total of 12 certificates, 5 of which are twenty dollar certificates and 7 of which are not twenty dollar certificates.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are drawing 2 times.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can draw:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "0 twenty dollar certificates on the first 2 draws. \n" ); document.write( "1 twenty dollar certificate on the first draw and 0 twenty dollar certificates on the second draw. \n" ); document.write( "0 twenty dollar certificates on the first draw and 1 twenty dollar certificate on the second draw. \n" ); document.write( "2 twenty dollar certificates on the first 2 draws.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "no other options are possible.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your probabilities will be as follows:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "0 twenty dollar certificates on the first 2 draws.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the probability will be 7/12 * 6/11 = 42/132.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 twenty dollar certificate on the first draw and 0 twenty dollar certificates on the second draw.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the probability will be 5/12 * 7/11 = 35/132.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "0 twenty dollar certificates on the first draw and 1 twenty dollar certificate on the second draw.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the probability will be 7/12 * 5/11 = 35/132.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2 twenty dollar certificates on the first 2 draws.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the probability will be 5/12 * 4/11 = 20/132.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your total probabilities will be (42 + 35 + 35 + 20) / 132 = 132/132 = 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since the sum of all probabilities in the probability distribution must be equal to 1, then this is as it should be.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |