for the 13th question:
To find the mystery number, we can look for the highest common factor of all the given factors.
Starting with the largest factor, 48, we check if it is divisible by each of the other factors. If it is, then it is the mystery number.
If 48 is not the mystery number, we move to the next largest factor, 24, and repeat the process.
Continuing in this way, we find that the mystery number is 24, since all of the other factors are factors of 24.
Therefore, the mystery number is 24.