Answer:
108 pounds of mulch.
64 pounds of gravel.
Step-by-step explanation:
Let x be the amount of mulch sold and y be the amount of gravel sold.
We have been given that a supplier sells 2 1/4 pounds of mulch for every 1 1/3 pounds of gravel.

We can represent this information as:

We are also told that the supplier sells 172 pounds of mulch and gravel combined. We can represent this information as:

From equation (1) we will get,


Substituting this value in equation (2) we will get,

Now let us have a common denominator.





Therefore, the supplier sold 64 pounds of gravel.
Upon substituting y=64 in equation (2) we will get,



Therefore, the supplier sold 108 pounds of mulch.