The LD (subscript 50) for a drug dose that would be fatal for 50% of the population. The LD (subscript 50)for aspirin in rats is 1.75 grams/kilogram of body weight. Calculate how many aspirin tablets a human weighing 155 pounds would have to take to reach this dosage. (1 aspirin = 5 grams = 325 mg)

Answer 1

It isn't clear in the problem that this is 1.75 g aspirin tablet/kg or 1.75 g active ingredient/kg.
I assume the problem means 1.75 g of active ingredient/kg body weight.
Convert 155 g body weight to kg. That will be 155 pounds x (2.2 kg/1 pound)= ?kg
Then kg body weight x (1 tablet/0.32g) = x tablets.