Question

Probability of Guessing the Right Password to Access the Account
Charan partially forgets his 4 digit ATM pin. He remembers the first two digits and knows that each of the last two digits are greater than five. The ATM will lock his account after three tries. If he randomly guesses the last two digits, what is the probability he will get access to his account? A. 1/2 B. 1/4 C. 3/16 D. 3/18 E. 1/32

Answer 1

Charan knows the first 2 digits and he knows the last two digits are greater then  5. 

So the last two digits will either be 6, 7, 8, or 9. 

So 

4 * 4 = 16 combinations 

3 chances to get the combinations... 

so 

C. 3/16 is the probabality.