Y = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}
Two integers will be randomly selected from the sets above, one integer from set Y and one integer from set B. What is the probability that the sum of the two integers will equal 9 ?  Answers
A) 0.15
B) 0.20
C) 0.25
D) 0.30
E) 0.33
The total number of pairs Y,B possible is   4*5= 
<gadget id="calculator">  4*5</gadget>
<output>20</output>
20. Out of these 20 pairs only 4 sum up to 9: (2, 7); (3, 6), (4, 5) and (5, 4). The probability thus is 4/20=0.2.   Answer: 0.20.
<result>B</result>
Y = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}
Two integers will be randomly selected from the sets above, one integer from set Y and one integer from set B. What is the probability that the sum of the two integers will equal 9 ?