Answer:- The weight of the arrow is 0.75 ounces.
Solution:- It is a unit conversion problem where we are asked to convert grains to ounces. We could easily do this conversion using two steps conversion, grains to pounds and pounds to ounces.
We know that, 1 pound = 7000 grains
1 pound = 16 ounces
Let's make the set up to convert 330 grains to ounces as:

= 0.75 ounces
So, the weight of 330 grains of arrow in ounces is 0.75.