A reduction of 25% in the price of oil enables a house wife to obtain 5kgs more for Rs.600, what is the reduced price for kg?
Choices: A) 30 B) 60 C) 70 D) 80 E) 20

Rationale: "a 600 * ( 25 / 100 ) = 150 - - - - 5 ? - - - - 1 = > rs . 30"
Answer: A