A cistern 8 m long and 6 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:	Choose one:
A) 80 m 2  B) 50 m 2  C) 83 m 2  D) 86 m 2  E) 55 m 2

Rationale: area of the wet surface = [ 2 ( lb + bh + lh ) - lb ] = 2 ( bh + lh ) + lb = [ 2 ( 6 x 1.25 + 8 x 1.25 ) + 8 x 6 ] m 2 = 83 m 2 . answer : c
Answer: C