Given:
The adult dosage is 75mg and the age of the child is 12.
The formula to find the child's dosage is

where a is the child's age, d is the usual adult's dosage and C is the child's dosage.
Required:
We need to find the child's dosage.
Step-by-step explanation:
Consider the formula to find the child's dosage.

Substitute a =12 and d =75 in the formula.


Final answer:
The child's dosage is 37.5mg.