Concept:Probability distribution of a discrete random variable using combinations from a finite set.
Explanation:Total batteries in the box
=8.
Defective batteries
=3, non-defective batteries
=8−3=5.
Let
X be the number of defective batteries selected when 2 batteries are drawn randomly.
Possible values of
X are
0,1,2.
Total ways to select 2 batteries from 8:
8C2=28×7=28For
X=0: both selected batteries are non-defective.
P(X=0)=8C25C2=2810For
X=1: one defective and one non-defective battery are selected.
P(X=1)=8C23C1×5C1=2815For
X=2: both selected batteries are defective.
P(X=2)=8C23C2=283Hence the distribution for
X=0,1,2 has probabilities
2810,2815,283 respectively.
Answer:The correct probability distribution is given in Option A.