2 corner most boxes of a chess board(diagonally opposite) haven been cut out
there's a rectangular block = 2 sqaures of chess board , how many such blocks can be placed on the chess board ?”
Choose one.
A) 27
B) 28
C) 29
D) 30
E) 31

Rationale: chess board has 64 squares . so we can place 32 rectangular blocks , but 2 are cut off from the corner . hence 32 - 2 = 30 blocks answer : d
Answer: D