In what ratio should a variety of rice costing Rs. 6 per kg be mixed with another variety of rice costing Rs. 8.75 per kg to obtain a mixture costing Rs. 7.50 per kg?	Choose the correct choice from the following: A) 1 / 68 B) 62 / 89 C) 12 / 68 D) 11 / 84 E) 5 / 6

Rationale: "explanation : let us say the ratio of the quantities of cheaper and dearer varieties = x : y by the rule of allegation , x / y = ( 87.5 - 7.50 ) / ( 7.50 - 6 ) = 5 / 6 answer : e"
Answer: E