Question

A device produces random 64-bit integers at a rate of one billion per second. After how many years of running is it unavoidable that the device produces an output for the second time? Round to the nearest number of years.

Answer 1

Answer:

3171 × 10^(44) years

Step-by-step explanation:

For each bit, since we are looking how many years of running it is unavoidable that the device produces an output for the second time, the possible integers are from 0 to 9. This is 10 possible integers for each bit.

Thus, total number of possible 64 bit integers = 10^(64) integers

Now, we are told that the device produces random integers at a rate of one billion per second (10^(9) billion per second)

Let's calculate how many it can produce in a year.

1 year = 365 × 24 × 60 × 60 seconds = 31,536,000 seconds

Thus, per year it will produce;

(10^(9) billion per second) × 31,536,000 seconds = 3.1536 × 10^(16)

Thus;

Number of years of running is it unavoidable that the device produces an output for the second time is;

(10^(64))/(3.1536 × 10^(16)) = 3171 × 10^(44) years