Answer : P(second resistor is 100ω , given that the first resistor is 50ω) is given by

Explanation :
Since we have given that
Total number of resistors =15
Number of resistors labelled with 50ω = 12
Number of resistors labelled with 100ω =3
Let A: Event getting resistor with 50ω
B: Event getting resistor with 100ω
Since A and B are independent events .
So,

Now, According to question , we can get that

So,

So, by using the conditional probability , which state that


So, P(second resistor is 100ω , given that the first resistor is 50ω) is given by
