Question 1: We have to identify which of given expressions are rational expressions.
1.

= 4.368
=

This is expressed in the form of
where p and q are integers, where q is not equal to zero.
Hence, it is rational.
2.

=

= 15
=
which is also expressed in the form of
where p and q are integers, where q is not equal to zero.
Hence, it is rational.
3.

=

which can not be expressed in the form of
where p and q are integers and q is not equal to zero.
Hence, it is not rational.
4. 4+5
= 9
=
which is also expressed in the form of
where p and q are integers, where q is not equal to zero.
Hence, it is rational.
5.

This expression can be rational and can not be rational. It depends on the value of 'n'.
Question 2:
Molli purchased 9 apples for $3.96.
Then, Molli divided $3.96 by 9.
Since, the cost of 9 apples = $3.96
If we have to find the cost of 1 apple, then we will divide the cost of 9 apples by the number of apples purchased.
Therefore, Cost of 1 apple = $3.96

= 0.44
Therefore, Molli divided $3.96 by 9 in order to find out how much she paid per apple.
Therefore, Option 1 is the correct answer.