Answer:
200 nm
Explanation:
We need a constructive interference to see the bright reflection
we know that
where m=1 and
is the wavelength of the gasoline
so 
putting the value of m and
in thickness equation

so the thickness of the film will be 200 nm
A link is a popular way to describe relationships in a relational database.
There are three types of relationships (links) between tables:
1. One-to-one <span>relationship , that allows only one record on each side of the relationship.
2. </span>One-to-many <span>relationship, that allows a single record in one table to be related to multiple records in another table.
3. </span>Many-to-many<span> relationship, in which many records in a table can link to many records in another table. F</span>
The correct answer or solution to the question above is marked A
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