Question 1103606
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Rate of work of A is {{{1/8}}} of the job per hour; of B is {{{1/10}}} and of C {{{1/12}}} of the job per hour.

When A and B worked together for 1 hour, they completed {{{1/8+1/10}}} = {{{5/40 + 4/40}}} = {{{9/40}}} of the job.

Hence, {{{1-9/40}}} = {{{31/40}}} of the work remained uncompleted.


The combined rate of work for B and C is {{{1/10+1/12}}} = {{{6/60+5/60}}} = {{{11/60}}}.


So, the answer to the problem question is this ratio  {{{((31/40))/((11/60))}}} = {{{(31*60)/(11*40)}}} = {{{(31*3)/(11*2)}}} = {{{93/22}}} hours = {{{4}}}{{{5/22}}} hours.
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