Mala and Usha shared their water from a bottle. If mala and usha both drank for the same amount of time, but usha only drank 2/10 of the total bottle, what was the ratio of mala and usha speed? Choose the correct choice from the following answers:  A) 1 : 4  B) 2 : 5  C) 4 : 1  D) 3 : 5  E) 2 : 3

Rationale: the answer is suppose to be c . 4 : 1 . it ' s from the gmatprep answer : option c
Answer: C