Question

the father of Maria is X years old which expression best represents Maria age is she is 1/3 of her father's age

Answer 1

If Maria's age is 1/3 of her father's age, and her father's age is X, the expression that represents Maria's age is just the product of X by the factor 1/3:

$\frac{1}{3}\cdot X=\frac{X}{3}$

So Maria's age is X/3