9th Class Mathematics Probability Question Bank Probability

Direction: for question number 14 ? 17. If A and B be two mutually exclusive events in a sample space such that. \[\operatorname{P}(A)\,=\frac{2}{5}\]and \[\operatorname{P}(B)\,=\frac{1}{2}\] then

Find \[\operatorname{P}\left( A\,\cup B \right)\]:

A) \[\frac{7}{16}\]

B) \[\frac{9}{16}\]

C) \[\frac{9}{10}\]

D)        \[\frac{1}{2}\]

E) None of these

Correct Answer: C

Solution :

Explanation Option [c] is correct. \[(A\cup B)=P(A)+P(B)-P(A\cap B)\] \[\frac{2}{5}+\frac{1}{2}-0=\frac{9}{10}\]\[(\therefore \,\,P(A\cap B)=0)\]