Consider the triangle (<em>in </em><em>which </em><em>angle</em><em>4</em><em> </em><em>is </em><em>present</em>)
by angle sum property,
20 + 40 + angle4 = 180
60 + angle4 = 180
angle4 = 180 - 60
angle4 = 120
Also,
angle2 = 120 (vertically opposite angles)
angle1 + angle2 = 180 (linear pair)
angle1 + 120 = 180
angle1 = 180 - 120
angle1 = 60
Current value of the boat = $45000
Rate at which the value decrease = 8.5%
Value decreased after 1 year = 
Hence, value becomes = 
Value decreased after 2nd year =

Hence, value becomes = 
Value decreased after 3 year =

Hence, value becomes = 
So, value of the boat after 3 years becomes $34472.74
Answer:
The word "of" in the question means multiply, so you need to multiple these two fractions.
2/3 x 4/5 = 8/15