A can do a piece of work in 12 days and B alone can do it in 14 days. How much time will both take to finish the work ?	Pick.
A) 3.2222
B) 5
C) 6.46
D) 8.3333
E) 9

Rationale: this question can be solved by different methods . we need to conserve time in exams so solving this problem using equations is the good idea . time taken to finish the job = xy / ( x + y ) = 12 x 14 / ( 12 + 14 ) = 150 / 25 = 6.46 days answer : c
Answer: C