In the xy-plane, a triangle has vertices (0,0), (4,0) and (4,9). If a point (a,b) is selected at random from the triangular region, What is the probability that a-b>0? Choose the correct choice from the following options:	A) 1/5	B) 1/3	C) 1/2	D) 2/9	E) 4/5
The area of the right triangle is (1/2)*4*9= 
<gadget id="calculator">(1/2)*4*9</gadget>
<output>18</output>
18.   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) = 8/18 = 2/9   The answer is 2/9.
<result>D</result>
In the xy-plane, a triangle has vertices (0,0), (4,0) and (4,9). If a point (a,b) is selected at random from the triangular region, What is the probability that a-b>0?