Found 7 solutions by MathLover1, ikleyn, josgarithmetic, greenestamps, MathTherapy, Edwin McCravy, mccravyedwin:
Answer by MathLover1(20850) (Show Source): You can put this solution on YOUR website!
it will take him approximately days
Answer by ikleyn(52873) (Show Source): You can put this solution on YOUR website!
.
A farmer ploughs his land in 12 days if he uses 5 tractors
How long will it take if he uses only 3 tractors ?
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The entire job is 12*5 = 60 tractor-days.
With using only 3 tractors, it will take = 20 days to complete the job. ANSWER
Solved (correctly) and the solution is as simple as a cucumber.
In this form, the solution is accessible to everyone, even to very young beginner students of the 4th grade,
who already know how to multiply and divide integer numbers, but do not yet know either fractions,
or proportions, or inverse proportions, or equations. What they need is to develop their common sense.
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Tutor @greenestamps asks in his post, how one farmer can operate multiple tractors at the same time ?
I think that in this problem, it is assumed that a farmer works/acts as a capitalist
and hires as many tractorists, as it is needed to drive as many tractors as it is required.
So, it is a very normal and very usual scheme on how things work here,
so there is no much sense to worry about it . . .
Answer by josgarithmetic(39629) (Show Source): You can put this solution on YOUR website!
First Part
1 job is, "plough his land".
r for work rate of just a single tractor
Second Part,
3 tractors instead of 5 tractors
t, how many days, unknown
Answer by greenestamps(13208) (Show Source): You can put this solution on YOUR website!
It should be obvious that the amount of time is inversely proportional to the number of tractors -- more tractors means less time; fewer tractors means more time.
The same job with 3/5 as many tractors is going to take 5/3 as long....
ANSWER: 20 days
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Note if we wanted to be REALLY picky about the wording of the problem, we could question how it is possible for THE (one single) farmer to operate multiple tractors at the same time....
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Tutor @MathTherapy, you need to get some therapy for your rude and arrogant behavior.
The statement of the problem says that THE farmer (a single person) plows his field in 12 days if HE uses 5 tractors.
I am NOT a buffoon or an idiot if I point that out in my response, saying that in doing so I am being picky.
Look at yourself in the mirror and see what kind of label you can put on yourself.
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And for tutor @ikleyn....
OF COURSE the problem implies that there need to be as many tractor drivers as there are tractors. There is nothing inappropriate in my pointing out that the problem is worded carelessly.
Answer by MathTherapy(10556) (Show Source): You can put this solution on YOUR website!
A farmer ploughs his land in 12 days if he uses 5 tractors how long will it take if he uses only 3 tractors
How R-I-D-I-C-U-L-O-U-S it is that a person who claims to want to help people in math would think that
a smaller number of tractors could go the job of 5 tractors, in less time!!
Then, another IDIOT/BUFFOON wants to know how 1 farmer can operate more than 1 tractor.
UNBELIEVABLE!!
Answer by Edwin McCravy(20063) (Show Source): You can put this solution on YOUR website!
As the tutors fight each other for egos, I'll reword the question:
A farmer ploughs his land in 12 days if he uses 5 tractors (with operators)
how long will it take if he uses only 3 tractors (with operators).
They've already solved it, but let's use the "worker-time-job" formula,
which even takes into account the number of jobs required to be done.
In this case the number of jobs to be done in both situations is 1, so
J1 = J2 = 1.
where
W1 = the number of workers in the first situation.
T1 = the number of time units (days in this problem) in the first situation.
J1 = the number of jobs in the first situation.
W2 = the number of workers in the second situation.
T2 = the number of time units (days) in the second situation.
J2 = the number of jobs in the second situation.
W1 = 5 W2 = 3
T1 = 12 T2 = the unknown quantity
J1 = 1 J2 = 1
Answer: 20 days.
Edwin
Answer by mccravyedwin(408) (Show Source): You can put this solution on YOUR website!
A farmer ploughs his land in 12 days if he uses 5 tractors (with operators)
how long will it take if he uses only 3 tractors (with operators).
If he used only 1 tractor (with operator), it would take him 5 times as long,
or 60 days.
But if he used 3 tractors (with operators), it would take him only 1/3 that long,
and 1/3 of 60 days is 20 days.
Edwin
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