Angela, Bernie, and Colleen can complete a job, all working together, in 3 hours. Angela and Bernie, working together at their respective rates, can complete the same job in 5 hours. How long would it take Colleen, working alone, to complete the entire job?	Select.
A) 7.5 hours B) 10 hours C) 12 hours D) 16 hours E) 20 hours
A+B+C complete the job in 3 hours.   A+B complete the job in 5 hours.   A+B and C complete the job in 3 hours --&gt;1/(A+B) + 1/C = 1/3--&gt;1/5+1/C=1/3 ----&gt; C=7.5 hours. 7.5 hoursNS 7.5 hours
<result>A</result>
Angela, Bernie, and Colleen can complete a job, all working together, in 3 hours. Angela and Bernie, working together at their respective rates, can complete the same job in 5 hours. How long would it take Colleen, working alone, to complete the entire job?