<PRE><B>Question 509871</B>
12 dishes...............3.5 minutes
12/12 dishes...............3.5/12 minutes
1 dish .................3.5/12 minutes
21*1 dish .................21*(3.5/12) minutes
21 dises................21*(3.5)/12 minutes
21 dises................7*(3.5)/4 minutes
21 dises................24.5/4 minutes
21 dises................6.125 minutes


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