A man purchased 4 blankets @ Rs.100 each, 5 blankets @ Rs.150 each and two blankets at a certain rate which is now slipped off from his memory. But he remembers that the average price of the blankets was Rs.150. Find the unknown rate of two blankets?  Choose one:  A) 300  B) 350  C) 450  D) 470  E) 500

Rationale: "explanation : 10 * 150 = 1500 4 * 100 + 5 * 150 = 1150 1500 – 1150 = 350 b"
Answer: B