document.write( "Question 1118905: The time it takes me to wash the dishes is uniformly distributed between 11 minutes and 21 minutes.\r
\n" ); document.write( "\n" ); document.write( "What is the probability that washing dishes tonight will take me between 13 and 19 minutes? \n" ); document.write( "

Algebra.Com's Answer #734659 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "Time interval duration \"between 11 minutes and 21 minutes\" is 10 minutes:\r\n" );
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document.write( "     1 minute from 11 min. to 12 min.\r\n" );
document.write( "     1 minute from 12 min. to 13 min.\r\n" );
document.write( "     1 minute from 13 min. to 14 min.\r\n" );
document.write( "     1 minute from 14 min. to 15 min.\r\n" );
document.write( "     1 minute from 15 min. to 16 min.\r\n" );
document.write( "     1 minute from 16 min. to 17 min.\r\n" );
document.write( "     1 minute from 17 min. to 18 min.\r\n" );
document.write( "     1 minute from 18 min. to 19 min.\r\n" );
document.write( "     1 minute from 19 min. to 20 min.\r\n" );
document.write( "     1 minute from 20 min. to 21 min.\r\n" );
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document.write( "Time interval duration \"between 13 minutes and 19 minutes\" is 6 minutes:\r\n" );
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document.write( "     1 minute from 13 min. to 14 min.\r\n" );
document.write( "     1 minute from 14 min. to 15 min.\r\n" );
document.write( "     1 minute from 15 min. to 16 min.\r\n" );
document.write( "     1 minute from 16 min. to 17 min.\r\n" );
document.write( "     1 minute from 17 min. to 18 min.\r\n" );
document.write( "     1 minute from 18 min. to 19 min.\r\n" );
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document.write( "The probability under the question is the ratio of 6 minutes to 10 minutes   = 0.6 = 60%.\r\n" );
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\n" ); document.write( "\n" ); document.write( "The solution and the answer by the other tutor are incorrect.\r
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\n" ); document.write( "\n" ); document.write( " After reading the @greenestamps solution I added this NOTICE.\r
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\n" ); document.write( "\n" ); document.write( "The meaning of this problem is THIS:\r
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document.write( "    I have a stop watch. I turn it on when I start dish washing, and I stop it when the process ends.\r\n" );
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document.write( "    I write the reading of the stop watch after every/each experiment.\r\n" );
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document.write( "    Then I see that the readings for the process duration are uniformly distributed over the time interval between 11 minutes \r\n" );
document.write( "    (=from the start of the 11-th minute reading) and 21 minutes (=to the complete end of the 20-th minute, \r\n" );
document.write( "    i.e. to the moment, when 21-th minute starts).\r\n" );
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document.write( "     . . . And so on to the end of the condition.\r\n" );
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\n" ); document.write( "\n" ); document.write( " This problem HAS THIS and ONLY THIS reading and meaning.\r
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\n" ); document.write( "\n" ); document.write( " Nothing else. // The words \"uniformly distributed\" of the condition do not leave the place (the gap) for any other interpretation.\r
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\n" ); document.write( "\n" ); document.write( " Any different interpretation is FALSE and IRRELEVANT.\r
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\n" ); document.write( "\n" ); document.write( " In particular, the proposed by @greenestamps interpretation is wrong.\r
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\n" ); document.write( "\n" ); document.write( "I agree that the problem formulation is not perfect, since it does not determine if 21-th minute is included completely or not. \r
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\n" ); document.write( "\n" ); document.write( "If it is included (as well as the 19-th minutes is fully included), then the answer is $\"7%2F11\"$ .\r
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\n" ); document.write( "\n" ); document.write( "But in any case two continuous time intervals are considered, and there is no place for a \"discrete\" interpretation.\r
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\n" ); document.write( "\n" ); document.write( "It is a STANDARD introductory problem on geometric probability.\r
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\n" ); document.write( "\n" ); document.write( "To see other similar solved problems, look into the lesson\r
\n" ); document.write( "\n" ); document.write( " - Geometric probability problems \r
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