Question:
A and B can do a work in 12 days ,B and C in 15 days and C and A in 20 days. If A ,B , C work together, they will complete the work in :
[This Maths Time and Work Question asked in following exams-
· SSC CGL 1999
· SSC CGL 2006
· SSC CGL 2013
· SSC CPO 2003
· SSC CPO 2006]
Options:
(1)5 days
(2)7(5/6) days
(3)10 days
(4)15 2/3 days
Answer: (3)10 days
Step By Step Explanation:
Given that:
· A and B can do a work in 12 days
· B and C in 15 days
· C and A in 20 days
so, A +B)'s one day work =1/12
Similarly ,
(B+C)'s one day work =1/15
and (C+A)'s one day work =1/20
so, 2(A+B+C)'s one day work
=1/12 +1/15+ 1/20=10+8+6/120 =1/5
so, (A+B+C)'s one day work
=1/10
so, A,B,C together can finish the whole work in 10 days.
Hence, Option(3) is correct answer.
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