Question

A two-digit locker combination has two nonzero digits and no digit is repeated in the combination.

Answer 1

Answer:

P(B|A) = 0.9

Step-by-step explanation:

Given -

Event A=the first digit is less than 7 =   { 1,2,3,4,5,6 }

we cant choose 0 for first digit then the total no of outcome for first digit is 9

then P(A) =   $\frac{6}{9}$

Event B=the second digit is less than 7 = {0, 1,2,3,4,5,6 }

then P(B)  = $\frac{7}{10}$

$B\bigcap A$ =  { 1,2,3,4,5,6 }

$P(B\bigcap A) = \frac{6}{10}$

P(B|A) = $\frac{P(B\bigcap A) }{P(A)}$

            = $\frac{\frac{6}{10}}{\frac{6}{9}}$

             = $\frac{9}{10}$ = .9