Work Step by Step
Doug is working at 1/15 = .067 jobs per minute while Betty is working at 1/10=.1 jobs per minute. Thus: $ 1 = .067t + .1t \\ 1 = .167t \\ t =6$
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.