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Janet can do a job in 3 hours while Garry can do the same job in 2 hours. If Janet works for an hour before Garry began helping her, how long will it take them to do the job?    hour (s)

 

not 4/5 hours

 

 

 

 

For each of the given statements:

• Determine the values of x for which each statement is true.

• Show the set of all points corresponding to the values of x on a number line.

 

x=|x|

 

"Example" .  x<-3:3 7

 Aug 15, 2019
 #1
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+1

The fraction of the  job that Janet can do in one hour  = 1/3

So...if she works for 1  hour  prior to Garry joining in, the fraction of the  job left to complete is  1  - 1/3   = 2/3

And the fraction of the job that Garry can do in one hour  = 1/2

 

So.....we have that    rate * time   =  fraction of job done...so... 

 

(1/3)x  + (1/2)x   =  2/3    simplify

 

(5/6)x  = 2/3     multiply both sides  by   6/5

 

x = (2/3) (6/5)   =  12/15   =  4/5 hours

 

So.....the total number of hours spent on the  job  =  1 hour  + 4/5 hours  =   9/5 hours

 

 

cool cool cool

 Aug 15, 2019
edited by CPhill  Aug 15, 2019

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