Question 69

Amit Kumar got a 4-digit pass code (which is formed out of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9) of his ATM card from ICICI Bank. But after the 50th day he lost the pass code and also forgot the number. How many maximum number of trials may he have to take to get the right number? 0 can be the beginning of the code number

Solution

Pass code : _ _ _ _

Now, all these four places can be filled with any of the 10 numbers, since repetition is allowed, and 0 can be the first digit.

Thus, maximum number of attempts = $$10\times10\times10\times10=(10)^4$$

=> Ans - (B)

Create a FREE account and get: