Let's list the given information. The frictional force, denoted as Ff, is equal to 0.200 N. We have to find the normal force, denoted as Fn. The relationship between Ff and Fn is written as:
Ff = μFn
where μ is the coefficient of friction
If there is no given data for μ, we can't solve this problem. Suppose μ = 0.5, then the normal force would be:
Fn = Ff/μ = 0.2/0.5 = 0.4 N