You forget the last two digits of your

cell phone password.
a. What is the probability that you randomly choose
the correct digits?
b. Suppose you remember that both digits are even. How
does this change the probability that you choose the
correct digits?

1 answer

I googled "number of possible passcodes" and it told be
10,000 which is 10^4, so there are no restrictions

your prob of the event you are after = 10^2/10^4 = 1/100

Assuming you count 0 as "even" , then you only have 5 choices at each of the last places
prob = 5^2/10^2 = 25/10000= 1/3600

otherwise, if 0 is not counted as even
prob = 16/10000 = 1/5625

you decide about the 0