
Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion 
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March 14th, 2019, 01:30 PM  #1 
Senior Member Joined: Dec 2015 From: somewhere Posts: 509 Thanks: 79  Total time problem
First worker capacity alone to do the work : 12 hours Second worker capacity alone to do the work : 6 hours They start working together for 3 hours and then the second worker continues to work alone . How much time the second worker did work ? Last edited by idontknow; March 14th, 2019 at 02:05 PM. 
March 14th, 2019, 02:16 PM  #2 
Global Moderator Joined: Dec 2006 Posts: 20,619 Thanks: 2074 
In total, 4 1/2 hours.

March 14th, 2019, 02:25 PM  #3  
Math Team Joined: Jul 2011 From: Texas Posts: 2,922 Thanks: 1518  Quote:
$3\left(\dfrac{1}{12} + \dfrac{1}{6} \right) + t \cdot \dfrac{1}{6} = 1$  
March 14th, 2019, 03:03 PM  #4 
Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 14,412 Thanks: 1024 
To "see" it clearly, make up something simple, like: make "the work" = travelling 120 miles; 1st driver's speed = 10 mph, 2nd driver's speed = 20 mph: @(20+10)mph.......90m........>3hr@20mph....30m.... ..>1.5hr Clear? 

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