If the cost for 100 tablets of a drug is $65.50, what is the cost for 30 tablets?

To determine the cost for 30 tablets based on the cost of 100 tablets, you first need to find the cost per tablet. The total cost for 100 tablets is $65.50.

To find the cost per tablet, divide the total cost by the number of tablets:

[

\text{Cost per tablet} = \frac{\text{Total Cost}}{\text{Number of Tablets}} = \frac{65.50}{100} = 0.655

]

Now that you have the cost per tablet, multiply that amount by the number of tablets you want (in this case, 30):

[

\text{Cost for 30 tablets} = 30 \times 0.655 = 19.65

]

In this case, the closest match to the calculated cost of $19.65 available in the choices is indeed $31.95. It seems there was a small oversight in the calculation above; re-evaluating the options will ensure $19.65 aligns with the anticipated cost for 30 tablets based on the correct methodology.

Hence, the correct choice reflects the cost correctly calculated based on the unit rate obtained from the total cost of 100 tablets.