A cistern 6m long and 5 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:  Choose the correct choice from the following answers.
A) 49 m 2 B) 50 m 2 C) 53.5 m 2 D) 55 m 2 E) 57.5 m 2

Rationale: "area of the wet surface = [ 2 ( lb + bh + lh ) - lb ] = 2 ( bh + lh ) + lb = [ 2 ( 5 x 1.25 + 6 x 1.25 ) + 6 x 5 ] m 2 = 57.5 m 2 . answer : option e"
Answer: E