A cistern 4 meters long and 4 meters wide contains water up to a depth of 1 meter 25 cm. What is the total area of the wet surface? Choose the correct answer.
A) 28 B) 32 C) 36 D) 40 E) 44

Rationale: "area of the wet surface = [ 2 ( lb + bh + lh ) - lb ] = 2 ( bh + lh ) + lb = [ 2 ( 4 x 1.25 + 4 x 1.25 ) + 4 x 4 ] = 36 the answer is c ."
Answer: C