SOLUTION: A farmer working together with his son needs 3 hours to plow a field. The farmer working alone can plow the field in 4 hours. How long would it take the son working alone to plow t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A farmer working together with his son needs 3 hours to plow a field. The farmer working alone can plow the field in 4 hours. How long would it take the son working alone to plow t      Log On


   



Question 248813: A farmer working together with his son needs 3 hours to plow a field. The farmer working alone can plow the field in 4 hours. How long would it take the son working alone to plow the field?
I need the rate of work (R), the time of work (T) , and the work done (W)
the equation is RT = W.
It would help if I am provided a detailed explanation

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
Farmer does 1/4 the job in 1 hour.
Both do 1/3 the job in 1 hr.
Let the son do 1/x the job in 1 hr.
.
1/4 + 1/x = 1/3
3x+12=4x multiply each side by 12x (LCM) to eliminate fractions.
x=12 hrs it takes the son to do the job alone.
.
Ed