To open the chest of shells the souvenir merchant must enter a code. As his memory is poor, to remember the code he has filled in this speech bubble so that every statement is correct. What is the code?

? X number 1,
? X number 2,
? X number 3,
? X number 4.

The multipliers are the numbers 1,2,3,4,5, or 6.

The hints are,

None of the numbers of the code is greater than 4.
Number 4 ony features once.
The numbers 1 and 3 are present twice.

To find the code for opening the chest of shells, we can follow the given hints and conditions:

1. None of the numbers of the code is greater than 4.

Looking at the possible multipliers (1, 2, 3, 4, 5, or 6), we can eliminate 5 and 6. Therefore, we are left with 1, 2, 3, and 4 as the potential code numbers.

2. Number 4 only features once.

Since the number 4 appears only once, we can eliminate any combination that has 4 appearing more than once.

3. The numbers 1 and 3 are present twice.

Based on this hint, we know that both 1 and 3 should appear twice in the code.

Considering all the hints, we can narrow down the possible combinations to:

1 1 3 3
1 3 1 3
3 1 1 3
3 3 1 1

These are the four potential codes that satisfy the given conditions. To determine the correct code, we may need additional information or context that has not been provided in the question.