A cistern 5m long and 4 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:
Choose the most appropriate option.
A) 49 m 2	B) 42.5 m 2	C) 53.5 m 2	D) 55 m 2	E) 57 m 2

Rationale: "area of the wet surface = [ 2 ( lb + bh + lh ) - lb ] = 2 ( bh + lh ) + lb = [ 2 ( 4 x 1.25 + 5 x 1.25 ) + 5 x 4 ] m 2 = 42.5 m 2 . answer : option b"
Answer: B