In the xy-plane, a triangle has vertices (0,0), (4,0) and (4,6). If a point (a,b) is selected at random from the triangular region, What is the probability that a-b>0?  Choose the correct answer:
A) 1/5
B) 1/3
C) 1/2
D) 2/3
E) 4/5
The area of the right triangle is (1/2)*4*6= 
<gadget id="calculator">(1/2)*4*6</gadget>
<output>12</output>
12.   Only the points (a,b) below the line y=x satisfy a - b &gt; 0.   The part of the triangle which is below the line y=x has an area of (1/2)(4)(4) = 8.   P(a - b &gt; 0) = 8/12 = 2/3   The answer is 2/3.
<result>D</result>
In the xy-plane, a triangle has vertices (0,0), (4,0) and (4,6). If a point (a,b) is selected at random from the triangular region, What is the probability that a-b>0?