A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :
Answer & explanation
Correct answer: option 1
Efficiency of A = 2 and B = 1 (as, A works twice as fast as B)
Efficiency of A + B = 3
Days required by A and B together to complete the work: \(\frac{12 }{3 }\) = 4 days