Sakshi can do a piece of work in 25 days.Tanya is 25% more efficient than Sakshi. The number of days taken by Tanya to do the same piece of work : Choose the correct choice from the following answers
A) 15  B) 20  C) 18  D) 25  E) 10

Rationale: "solution ratio of times taken by sakshi and tanya = 125 : 100 = 5 : 4 . suppose tanya taken x days to do the work . 5 : 4 : : 25 : x ⇒ x = ( 25 x 4 / 5 ) ⇒ x = 20 days . hence , tanya takes 16 days is complete the work . answer b"
Answer: B