How can this English sentence be translated into a logical expression? ( Translating " unless") 
You cannot ride the roller coaster if you are under 4 feet tall unless you are older than 16 years old.

Let:


*

*$P$ stands for "you can ride the roller coaster"

*$Q$ stands for "you are under 4 feet tall"

*$R$ stands for "you are older than 16 years old"
Is this logical expression correctly translated?
$$P \rightarrow (Q \wedge R)$$

Solution: let suppose 
q= You can ride the roller coaster;
p= you are older than 16 years old;
r= you are under 4 feet tall;
There is two states of “q if p” and “q if r”;
Because 
•   q unless p :: (the statement is as )
You can ride the roller coaster unless you are not older than 16 years old;
•   q, if r :: (the statement is as)
You can ride the roller coaster unless you are under 4 feet tall;
•   These two statements have same conclusion that is “you can ride a roller coaster” and the hypothesis are two.
So these two conclusions may be simplify in one statement as:
“You can ride the roller coaster, if you are under 4 feet tall and you are not older than 16 years old”
Then in this statement there is the (q, if p) form of implication and p which is the hypothesis has the operator “and” .So, the expression is 
Hypothesis -> conclusion as:
                (r ^ ~p) -> ~q
Where ~p means: you are not older than 16 years old” and 
~q means: You cannot ride the roller coaster.
