Sakshi can do a piece of work in 15 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:
A) 15
B) 16
C) 18
D) 12
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 : : 15 : x ⇒ x = ( 15 x 4 / 5 ) ⇒ x = 12 days . hence , tanya takes 16 days is complete the work . answer d"
Answer: D