SOLUTION: Kamal and Sunil needs 8 and 12 hours respectively to finish a certain task. Suppose they start working together and Kamal leaves after 4 hours. How long more will Sunil need to com

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Kamal and Sunil needs 8 and 12 hours respectively to finish a certain task. Suppose they start working together and Kamal leaves after 4 hours. How long more will Sunil need to com      Log On


   



Question 643435: Kamal and Sunil needs 8 and 12 hours respectively to finish a certain task. Suppose they start working together and Kamal leaves after 4 hours. How long more will Sunil need to complete the rest of the task?
Answer by sachi(548) About Me  (Show Source):
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Kamal and Sunil needs 8 and 12 hours respectively to finish a certain task
so in i hr kamal finishes 1/8 portion of the work
& sunil finishes 1/12 portion of the work
now in 1 hr they together finishes 1/8+1/12=)3+2)/24=5/24 portion of the work
in 4 hrs they will finish 4*5/24=20/24 portion
so the remaining portion of the work = 1-20/24=4/24 =1/6
now sunil finishes 1/12 portion of work in 1 hr
so he will finish 1/6 portion in 1/(1/12)*)1/6)=12/6= 2 hrs
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