Question 242796
This is a good question to have your calculator handy.
The hint is a key to getting started: 16 oz = 1 lb.
So, we know there are 15 1/2 lb = 15.5 lb = 15.5 lb * 16 oz/lb = 248.
(A quick reasonable check is to recall that 16*16 = 256.  So 15.5 * 16 should be about 8 less than 256.)
Now we have to package the seeds into bags weighing 3 1/4 = 3.25 oz each.
248 / 3.25 = 76.3.  So we use 76 bags at 3.25 oz each.
The total weight used = 3.25 * 76 = 247 oz.
So there will be 1 ounce of sunflower seeds left.