Question

What is the prescribed dosage of a certain medicine for a child 4 years old, if the adult dosage of the medicine is 180 milligrams? Round to the nearest whole number

Answer 1

40 mg

Explanation:

Given,

The prescribed dosage the medicine for an adult = 180 milligrams,

Since, the minimum age of an adult = 18 years,

So, the prescribed dosage of the medicine for 18 years old person = 180 milligrams,

Thus, the ratio of prescribed dosage of medicine ( in mg ) and age of person ( in years ) =
`(180)/(18)`

Suppose prescribed dosage of a certain medicine for a child 4 years old is x mg,

So, ratio of prescribed dosage of medicine and age =
`(x)/(4)`

`(x)/(4)=(180)/(18)`

`(x)/(4)=10`

`\implies x = 4* 10 = 40`

Hence, the prescribed dosage of a certain medicine for a child 4 years old would be 40 mg.