Pg 327 (339) - Q24
Remember we said that they like to ask you about 3-4-5 right triangles. Well, in triangle ABC, that line across the bottom AC that has a value of X+Y is the hypotenuse to a 3-4-5 right triangle. So, you have X+Y=5. Thus, Y/3=3/5. By cross multiplying, you find out that Y=9/5, or 1.8.