Probability

Question

Suppose that the probability that a student owns a smartphone is 0.7, the probability that they own a laptop is 0.6, and the probability that they own both is 0.5. What is the probability that a student owns either a smartphone or a laptop or both?

Answer 1

Answer:  P(Smartphone) +P(Laptop) - P(Smartphone AND Laptop)

 

Remember to use the property of AND combinations in probability problems, look it up if you must.

 

Good luck!

 

                    

Answer 2

Solve this by using a Venn diagram.

Draw two semi-overlapping circles, L and S.

Place the number 0.5 in the OVERLAPPING ('intersection') part of the figure.

Place 0.2 in the remaining part of the S circle; place 0.1 in the remaining part of the L circle.

P(L or S, or both) = 0.1+0.2+0.5 = 0.8