Some campers went rowing in the morning while w campers went rowing in the afternoon. If a total of x campers went rowing that day How many campers went rowing in the morning?
Let's say that the number of campers who went rowing in the morning is $m$, and the number of campers who went rowing in the afternoon is $a$. 

We know that the total number of campers who went rowing that day is $x$, so:
$$x = m + a$$
We also know that some campers went rowing in the morning, so:
$$m > 0$$
We also know that some campers went rowing in the afternoon, so:
$$a > 0$$
We also know that the number of campers who went rowing in the morning is less than the total number of campers who went rowing that day, so:
$$m < x$$
We also know that the number of campers who went rowing in the afternoon is less than the total number of campers who went rowing that day, so:
$$a < x$$

Now we have four inequalities with two unknowns, $m$ and $a$. We can solve this system of inequalities using substitution. 

Substitute $x = m + a$ into each of the other three inequalities:
$$m + a > 0