We are told that we need 1.5 cu yd of sand for every 100 sq yd of surface, then we can express the ratio of sand to surface like this:
[tex]\text{ratio}=\frac{1.5}{100}[/tex]In order to find how much sand we need for 350 sq yd of surface, we just have to multiply 350 by this ratio, then we get:
[tex]350\times\frac{1.5}{100}=5.25[/tex]Then, we need 5.25 cubic yards of sand.
