Answer:
a) The probability that a student has either a Visa card or a MasterCard is 0.71.
b) V and M are not independent.
Step-by-step explanation:
Given : The probability that a student has a Visa card (event V) is 0.63. The probability that a student has a MasterCard (event M) is 0.11. The probability that a student has both cards is 0.03.
To find :
a) The probability that a student has either a Visa card or a MasterCard ?
b) In this problem, are V and M independent ?
Solution :
The probability that a student has a visa card(event V) is P(V)= 0.63
The probability that a student has a MasterCard (event M) is P(M)= 0.11
The probability that a student has both cards is ![P(V \cap M)=0.03](https://tex.z-dn.net/?f=P%28V%20%5Ccap%20M%29%3D0.03)
a) Probability that a student has either a Visa card or a Master Card is given by,
![P(V \cup M) = P(V) + P(M) - P(V\cap M)](https://tex.z-dn.net/?f=P%28V%20%5Ccup%20M%29%20%3D%20P%28V%29%20%2B%20P%28M%29%20-%20P%28V%5Ccap%20M%29)
![P(V \cup M) = 0.63+ 0.11- 0.03](https://tex.z-dn.net/?f=P%28V%20%5Ccup%20M%29%20%3D%200.63%2B%200.11-%200.03)
![P(V \cup M) =0.74- 0.03](https://tex.z-dn.net/?f=P%28V%20%5Ccup%20M%29%20%3D0.74-%200.03)
![P(V \cup M) =0.71](https://tex.z-dn.net/?f=P%28V%20%5Ccup%20M%29%20%3D0.71)
The probability that a student has either a Visa card or a MasterCard is 0.71.
b) Two events, A and B, are independent if ![P(A\cap B)=P(A)P(B)](https://tex.z-dn.net/?f=P%28A%5Ccap%20B%29%3DP%28A%29P%28B%29)
For V and M to be independent the condition is satisfied,
![P(V\cap M)=P(V)P(M)](https://tex.z-dn.net/?f=P%28V%5Ccap%20M%29%3DP%28V%29P%28M%29)
Substitute the values,
![0.03=0.63\times 0.11](https://tex.z-dn.net/?f=0.03%3D0.63%5Ctimes%200.11)
![0.03\neq 0.0693](https://tex.z-dn.net/?f=0.03%5Cneq%200.0693)
So, V and M are not independent.