To determine the probability of guessing the correct combination for a 5-digit lock using numbers from 1 to 6, we first need to calculate the total number of possible combinations.
Each digit in the combination can be one of 6 numbers (1 through 6), and since there are 5 digits, the total number of combinations can be calculated using the formula:
\[ \text{Total combinations} = 6^5 \]
Calculating that:
\[ 6^5 = 6 \times 6 \times 6 \times 6 \times 6 = 7776 \]
Therefore, there are 7776 possible combinations.
When you are guessing, there is only 1 correct combination out of the 7776 possible combinations.
The probability of guessing the correct combination is therefore:
\[ \text{Probability} = \frac{1 \text{ (successful guess)}}{7776 \text{ (total combinations)}} = \frac{1}{7776} \]
Therefore, the correct answer is:
\[ \text{Probability} = \frac{1}{7776} \]