Step-by-step explanation:

15) Since B is 60% more efficient the rate of B is 1.6 x 1/12 = 1.6/12 = 16/120 = 2/15. Since time is inverse of rate, B can complete the job in 15/2 = 7.5 days. b2bt wrote: A can complete a certain job in 12 days. B is 60% more efficient than A.

16). Together they complete the work in 18 days

So, in one day they complete 1/18 work.

Since A is twice good as B

So A's workdone in one day= 2x

& B's workdone in one day= x

So, 2x + x = 1/18

3x = 1/18

X = 1/54

So, B's workdone in oneday= 1/54

& A's workdone in one day= 1/27

So, A alone will take 27 days to complete a piece of work

Ans: 27 days

Answer:

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