Question 956899
The experienced worker's rate is 
{{{ 80/1 }}} units/hr
The apprentice's rate is
{{{ ((3/5)*80 )/1 = 48/1 }}} units/hr
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Working together, 2 apprentices have a rate of:
{{{ ( 2*48 ) / 1 = 96 /1 }}} units/hr
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[ units ] / [ units/hr ] = hrs
{{{ 480 / 96 = 5 }}}
It will take 2 apprentices 5 hrs to finish
480 units of work