Question

$SetA=\{2,3,4,5\}$
$SetB=\{4,5,6,7,8\}$
Two integers will be randomly selected from the sets above, one integer from Set A and one integer from Set B. What is the probability that the sum of the two integers will equal 9?

• A. $0.10$
• B. $0.40$
• C. $0.20$
• D. $0.15$

Answer 1

Answer: (C)

$0.20$

Total cases possible for selection of two numbers: $4\times 5=20$

Total cases when sum of selected numbers is $9$ are: $4\to \left\{\right(2,7),(3,6),(4,5),(5,4\left)\right\}$

Required Probability:

$P=\frac{4}{20}=\frac{1}{5}$