An airplane is flying at a height of 900 m. The angle of depression of the airport A from the plane is 21 degrees. Calculate the horizontal distance between the airplane and the airport. Round to the nearest tenth.

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters