Question 993128
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{{{1/5}}} + {{{1/4}}} - {{{1/20}}} = {{{4/20 + 5/20 - 1/20}}} = {{{(4+5-1)/20}}} = {{{8/20}}} = {{{2/5}}}.


Hence, it will take {{{5/2}}} = {{{2}}}{{{1/2}}} hours.


It is a joint work problem.


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