Find the ratio in which rice at Rs. 7.20 a kg be mixed with rice at Rs. 5.70 a kg to produce a mixture worth Rs. 6.30 a kg.  Pick one
A) 1 : 2 B) 2 : 3 C) 3 : 4 D) 3 : 5 E) 4 : 5

Rationale: "req = 60 : 90 = 2 : 3 answer b"
Answer: B