Kate and her boyfriend Ben, completed the painting of their new apartment together in 6 days.If they were to work separately, how long will it take each of them to complete it, if Ben can complete the painting 5 days earlier than Kate.
Answers: A) 6 and 11 B) 5 and 10 C) 10 and 15 D) 8 and 13 E) 6 and 10
Work = (A)(B)/(A+B) where A and B are the individual times of each entity.   Here, we're told that (working together) the two workers would complete a job in 12 days. This means that (individually) each of them would take MORE than 10 days to do the job.   Answers E, A and C are illogical, since the individual times must both be greater than 10 days.   so we can TEST the values for Answers B and D.   Using the values for Answers C and D...   Answer 10 and 15: (10)(15)/(10+15) = 150/25= 
<gadget id="calculator">150/25</gadget>
<output>6</output>
6 This is a match   Final Answer:   10 and 15
<result>C</result>
Kate and her boyfriend Ben, completed the painting of their new apartment together in 6 days.If they were to work separately, how long will it take each of them to complete it, if Ben can complete the painting 5 days earlier than Kate.