A cistern 10 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 choice from the following options.
A) 45 B) 55 C) 65 D) 75 E) 85
Area of the wet surface = [2(lb + bh + lh) - lb]   = 2(bh + lh) + lb   = [2 (4 x 1.25 + 10 x 1.25) + 10 x 4]   = 75   The answer is 75.
<result>D</result>
A cistern 10 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?