We are given that the population of rabbits will double every month, this means that the first month there will be 2 rabbits:

Now, the second month is double the first:

For the third month is double the second:

If we continue like this we will notice that the number of rabbits given the number of months "n" is:

For "n = 7" we have:

Now, the number of livestock is the number of rabbits plus the 10 male cattle, therefore, the expression is:

Solving the expression:

Therefore, the number of livestock after 7 months is 138.