A cistern 7 m long and 5 m wide contains water up to a breadth of 1 m 40 cm. Find the total area of the wet surface.  Choices:
A) 69 m sqaure  B) 49 m sqaure  C) 52 m sqaure  D) 64 m sqaure  E) none of these

Rationale: "explanation : area of the wet surface = 2 [ lb + bh + hl ] - lb = 2 [ bh + hl ] + lb = 2 [ ( 5 * 1.40 + 7 * 1.40 ) ] + 7 * 5 = 69 m square option a"
Answer: A