Posted by **John** on Tuesday, February 19, 2013 at 2:23am.

Killer robots are trying to take over the world. They know the password to the doomsday weapon is 5 digits long and contains either 0 or 1, and either 2 or 3, and either 4 or 5, and either 6 or 7, and either 8 or 9. If the robots can enter 5 passwords per second, how long (in seconds) will it take them to go through all the possible passwords?

- Math -
**Reiny**, Tuesday, February 19, 2013 at 9:28am
I will assume the "password" may start with a 0

So let's first of all choose the number of passwords

which would be C(2,1) x C(2,1) x C(2,1) x C(2,1) x C(2,1)

= 2^5 = 32

13578 would be in that choice, but not 31578

So we now have to "arrange" each of these 32 numbers

which would give us 32 x 5! = 3840

at a rate of 5 passwords per second it would take

3840/5 or 768 seconds to crack it

## Answer this Question

## Related Questions

- maths - terrorists are trying to take over the world. They know the password to ...
- algebra - 2. The sum of both digits, of either of two two-digit numbers, in ...
- Math statistics - For a certain computer program a password must be exactly 5 ...
- Social Studies - The interaction of private companies trying to make the ...
- Math - Solve by either graphing and then get an exact solution by using either ...
- math - find the slope of the line, if it exists: coordinates are (-1,-5), (1,-5...
- English - HELP! John or Doris (write, Writes) to us regularly. Either Carol or ...
- MATH - THERE ARE 2 SPINNERS ONE IS LABLED A-D THE OTHER IS LABLED 1-8. WHAT IS ...
- Chemistry - The nuclide 12 N 7 is unstable. What type of radioactive decay would...
- computer programming - Write a program that simulates the dial of a phone number...

More Related Questions