Six books are labelled A, B, C, D, E and F and are placed side by side. Books B, C, E and F have green covers while others have yellow covers. Books A, B and D are new while the rest are old volumes. Books A, B and C are law reports while the rest are medical extracts. Which two books are old medical extracts and have green covers ?

To solve this elegantly, we look for the 'strongest' constraint that can filter the options.\n\nThe question asks for **Medical extracts** (among other things).\n\nThe statement says: 'Books A, B and C are law reports while the rest are medical extracts.'\nThis establishes a clear rule: **If a book is A, B, or C, it is a Law report, not a Medical extract.**\n\nTherefore, any option containing A, B, or C can be immediately eliminated.\n\nLet's check the options:\n(A) **B** and **C** -> Eliminate (Both are Law).\n(C) **C** and E -> Eliminate (C is Law).\n(D) **C** and F -> Eliminate (C is Law).\n\nWe are left with only **(B) E and F**.\n\nSanity Check: Are E and F 'Old' and 'Green'?\n- Green: Yes, list is B, C, **E, F**.\n- Old: Yes, New are A, B, D. So **E, F** are Old.\n\nThe logic holds perfectly. We didn't even need to process the 'Green' or 'Old' lists initially; the 'Law vs Medical' split was enough.