SOLUTION: If 5 farmers can plow 5 fields in 5 hours how many fields can 10 farmers plow in 10 hours?

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Question 529343: If 5 farmers can plow 5 fields in 5 hours how many fields can 10 farmers plow in 10 hours?
Found 2 solutions by oberobic, Edwin McCravy:
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
If 5 farmers can plow 5 fields in 5 hours, then each of them plows 1 field per 5 hours or 1/5 of a field per hour.
.
10 farmers * 1/5 field/hr * x hr = 10 fields
.
2x = 10
.
x = 5 hr
.
To check with each farmer working for 5 hr at 1/5 field/hr, each farmer will plow 1 field.
You've got 10 farmers, so they will plow 10 fields in 5 hrs.
.
Done.

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
If 5 farmers can plow 5 fields in 5 hours how many fields can 10 farmers plow in 10 hours?

The other tutor's solution is incorrect.

5 farmers can plow 5 fields in 5 hours

so twice as many farmers can plow twice as many fields in the same time, so

10 farmers can plow 10 fields in 5 hours

So in twice the time 10 farmers can plow twice as many fields, so

10 farmers can plow 20 fields in 10 hours

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Or you can use the "workers-times-jobs" formula:

%28W%5B1%5DT%5B1%5D%29%2FJ%5B1%5D = %28W%5B2%5DT%5B2%5D%29%2FJ%5B2%5D

where

W1 = number of workers in the first situation = 5
W2 = number of workers in the second situation = 10
T1 = number of time units in the first situation = 5
T2 = number of time units in the second situation = 10
J1 = number of jobs done in the first situation = 5
J2 = number of jobs done in the second situation = ?

%28W%5B1%5DT%5B1%5D%29%2FJ%5B1%5D = %28W%5B2%5DT%5B2%5D%29%2FJ%5B2%5D

Substituting:

%285%2A5%29%2F5 = %2810%2A10%29%2FJ%5B2%5D

%2825%29%2F5 = %28100%29%2FJ%5B2%5D

5 = %28100%29%2FJ%5B2%5D

5J2 = 100

J2 = 100%2F5

J2 = 20

Edwin