A locker combination consists of two nonzero digits, and each combination consists of different digits. Event A is defined as choosing an odd number as the first digit, and event B is defined as choosing an odd number as the second digit.

Question

If a combination is picked at random, with each possible locker combination being equally likely, what is P(A and B) expressed in simplest form?

A. 5/18
B. 4/9
C. 1/2
D. 5/9

Answer 1

So the digits can each be from 1 to 9, without repetition, of which 5 are odd
Your event is that both are odd
P(odd and odd) = (5/9)(4/8) = ....

Answer 2

so.... ti would be 5/18?

Answer 3

P(B|A)

(5/9) x (4/8) = 20/72

Reducing... we have... 5/18