The mean daily profit made by a shopkeeper in a month of 30 days was Rs. 350. If the mean profit for the first fifteen days was Rs. 225, then the mean profit for the last 15 days would be  Pick:
A) rs . 200
B) rs . 350
C) rs . 475
D) rs . 425
E) none of these

Rationale: "average would be : 350 = ( 225 + x ) / 2 on solving , x = 475 . answer : c"
Answer: C