Answer:
The (minimum) thickness of the oil slick is 325 nm.
Step-by-step explanation:
Let the (minimum) thickness of the oil slick =

Therefore:
2
= (
+
)*λ
/
(1)
similarly,
2
=(
)*λ
/
(2)
Thus, equation 1 = equation 2
(
+
*λ
= (
*λ

Where:
λ

λ


Therefore:
=650/390=5/3
This shows that,
=2
=1
Thus, using equation 2
=
