SOLUTION: Please help me to solve this word problem step by step. (((Sally runs the family farm in Boone, Iowa, She can plow the fields of the farm in 20hrs. Her daughter Brenda can plow th

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Question 147102: Please help me to solve this word problem step by step.
(((Sally runs the family farm in Boone, Iowa, She can plow the fields of the farm in 20hrs. Her daughter Brenda can plow the fields of the farm in 30hrs. If they have identical tractors, how long would it take Brenda and Sally to plow the fields of the farm if they worked together?)))
Found 2 solutions by ankor@dixie-net.com, josmiceli:
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
Simplify the problem
S can plow the fields of the farm in 20 hrs. B can plow the fields in 30 hrs. If they have identical tractors, how long would it take Brenda and Sally to plow the fields of the farm if they worked together?)))
:
Let t = time required if they work together
:
Let the completed job = 1; therefore, the fraction of the job that each do, = 1
:
+ = 1
:
Multiply each term by 60 to get rid of the fractions, solve for t
60* + 60* = 60(1)
Cancel out the denominators and you have:
:
3t + 2t = 60
:
5t = 60
t = ; divide both sides by 5
t = 12 hr working together.
:
:
Check solution by seeing if the fraction of the job each does, equals 1
+ =
.6 + .4 = 1

Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!
(1 field)/(Sally's time) + (1 field)/(Brenda's time) = (1 field)/(time together)

Multiply both sides by

Working together, they can plow the field in hrs