Arun and Tarun can do a work in 10 days.After 4 days tarun went to his village.How many days are required to complete the remaining work by Arun alone.Arun can do the work alone in 50 days.  Pick one:
A) 16 days .
B) 17 days .
C) 18 days .
D) 30 days .
E) 20 days .

Rationale: they together completed 4 / 10 work in 4 days . balance 6 / 10 work will be completed by arun alone in 50 * 6 / 10 = 30 days . answer : d
Answer: D