Manny can assemble a computer by himself in 50 minutes. lucy does the same job in 45 minutes. how long will it take to assemble a computer working together

Manny can assemble a computer in 50 minutes. That means, in a minute Manny does  job.

Lucy can assemble a computer in 45 minutes. That means, in a minute Lucy does  job.

If they are working together, in a minute they will do:



In a minute they will do  job

To finish the job they will do it in minutes or about 24 minutes.