a cistern 4 m long and 2 m wide contains water up to a depth of 1 m 25 cm . the total area of the wet surface is :
"area of the wet surface = [ 2 ( lb + bh + lh ) - lb ] = 2 ( bh + lh ) + lb = [ 2 ( 2 x 1.25 + 4 x 1.25 ) + 4 x 2 ] m 2 = 23 m 2 . answer : a"
add(multiply(const_2, add(multiply(add(divide(25, const_100), 1), 2), multiply(add(divide(25, const_100), 1), 4))), multiply(2, 4))