SOLUTION: doy and his son could do a job in 4 days. after they had worked for 3 days. day got sick and the son finished the task in 6 more days. how many days each is required to do the enti

Algebra ->  Rate-of-work-word-problems -> SOLUTION: doy and his son could do a job in 4 days. after they had worked for 3 days. day got sick and the son finished the task in 6 more days. how many days each is required to do the enti      Log On


   

Question 1058058: doy and his son could do a job in 4 days. after they had worked for 3 days. day got sick and the son finished the task in 6 more days. how many days each is required to do the entire task?
Found 3 solutions by josgarithmetic, ikleyn, MathTherapy:
Answer by josgarithmetic(39620) About Me  (Show Source):
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d days for Doy to do 1 job;
s days for Son to do 1 job;

system%28%281%2Fd%2B1%2Fs%29%2A3%2B%281%2Fs%29%2A6=1%2C%281%2Fd%2B1%2Fs%29=1%2F4%29
Not a linear system, but two equations in two unknown variables.

Answer by ikleyn(52800) About Me  (Show Source):
You can put this solution on YOUR website!
.
Doy and his son could do a job in 4 days. After they had worked for 3 days. day got sick and the son finished the task
in 6 more days. how many days each is required to do the entire task?
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After Doy and his son worked for 3 days, they made 3%2F4 of the entire job (by doing together 1%2F4 of the job per day).

As the condition says, the son completed the remaining 1%2F4 of the job in 6 days.
It means that the son can do (can complete) the entire job in 24 days.


OK, very good. Half of the problem is just solved.

Further, if the son can do 1%2F24 of the job in one day, he makes 4%2F24 = 1%2F6 of the work in 4 days. 

Hence, his father does 1+-+1%2F6 = 5%2F6 of the job in 4 days.

Therefore, the father makes 5%2F%284%2A6%29 = 5%2F24 of the work per day.

It follows that it will take 24%2F5 = 4 4%2F5 days for the father to complete the job working alone.

The lesson to learn from this solution:

     There is no need to solve equations.
     You can solve it using simple logic.
     You also are supposed to operate freely with fractions. That's all.

     Simple logic and fractions.


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There is a wide variety of similar solved joint-work problems with detailed explanations in the lessons
    - Using Fractions to solve word problems on joint work,
    - Solving more complicated word problems on joint work,
    - Selected joint-work word problems from the archive
in this site.

Read them and get be trained in solving joint-work problems.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Rate of work and joint work problems" of the section "Word problems".


Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

doy and his son could do a job in 4 days. after they had worked for 3 days. day got sick and the son finished the task in 6 more days. how many days each is required to do the entire task?