A is twice as efficient as B and together they can finish a work in 18 A alone
Answer: (1) 27 days
A is twice as efficient as B
Then, 2 A = B or A = B/2
They can finish a work in 18 days.
1/A + 1/2A = 1/18
3/2 A = 1/18
2 A = 54
A = 54/2
A = 27
A alone can finish the work = 27 days.
Hence, the correct answer is option (1) 27 days.