SOLUTION: if 1 person does a task in 10min and another does it in 20min how much time will they take if they work together

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Question 723075: if 1 person does a task in 10min and another does it in 20min how much time will they take if they work together
Answer by fcabanski(1391) About Me  (Show Source):
You can put this solution on YOUR website!
The first person does 1/10 of the task per minute. The second person does 1/20 of the task per minute. Together they do 1/10 + 1/20 = 2/20 + 1/20 = 3/20 of the task per minute. The whole task is 20/20.


Divide the whole task by the part they do per minute to find the necessary time.


20/20 / 3/20 = 20/20 * 20/3 = 20/3 = 6 and 2/3 minutes = 6 minutes and 40 seconds.