# Running out of lock.

**Number Theory**Level 1

It was the last day of the school year, and every student was requested to clear their lockers. Unfortunately, Jim forgot the code for the lock, and can not find a way to open it. However, a rude but smart guy named Jay know the code. Jay felt pitiful and decided to give Jim some clues to open it.

The clues are:

1. It is a 4-digit code.

2. The code consists of only 1-digit numbers.

2. The numbers are less than a 2-digit number.

3. The third number is half the 2-digit number.

4. The second number is 3

5. The sum of the second and the third number is the fourth number.

6. The half of the fourth number is equal to the first number.

7. The 2-digit number is the sum of the second and the fourth number minus one.

What is the code? What is the 2-digit number?

Write your answers in a form like this: abcd.ee

abcd is equal to the code, A being the first number and D being the last number

ee is equal to the 2 digit number.