sir said 4th is correct but i think 3 is correct.  according to me..... P1 = 2/3*P2 (P2 = Second = 9days, P1 = first = 6days)

which option is correct 3 or 4 ? & why A can complete a piece of work in 2 days. B takes double the time taken by A, C takes double that of B, and D takes double that of C to complete the same task. They are paired in groups of two each. One pair takes two thirds the time needed by the second pair to complete the work. Which is the first pair?(CAT)(1) A and B(2) A and C(3) B and C(4) A and D