SOLUTION: It takes a person 20 minutes to check a batch of 60 workers. An assistant can check the same batch in 30 minutes. How long should it take them working together? Simplest forma

Question 947895: It takes a person 20 minutes to check a batch of 60 workers. An assistant can check the same batch in 30 minutes. How long should it take them working together?
Simplest format please.
Answer by ptaylor(2198) (Show Source): You can put this solution on YOUR website!
It takes a person 20 minutes to check a batch of 60 workers. An assistant can check the same batch in 30 minutes. How long should it take them working together?
Let x=amount of time it takes them working together
Together they check at the rate of 1/x of the batch per min
The person checks at the rate of 1/20 batch per min
Assistant checks at the rate of 1/30 of the batch per min
Soooo
1/20 + 1/30= 1/x multiply each term by 60x
3x+2x=60
5x=60
x=12 min ---amount of time it takes them working together
CK
In 12 min person checks 12/20 of the batch
In 12 min assistant checks 12/30 of the batch
12/20 + 12/30 should equal 1 (1 batch, that is)
36/60+24/60=???1
60/60=1
1=1
Hope this helps----ptaylor

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