1, Water was added to aqueous solution of a certain salt with concertation of 20%, which resulted in a 20% mass increase of the solution Part of the water was then evaporated from the resulting solution and its mass decreased by 20%. What is the current concentration of this solution? 2.The height of the isosceles trapezoid ABCD from the vertex D of the obtuse angle divides the longer base into sections AE and EB of 3 cm and 13 cm respectively. The triangle AED is isosceles. Calculate the area of the trapezoid ABCD.