Kerosine $($n$1=1\mathrm{.}20)$ has been leaked into the Persian Gulf, creating a large slick on top

of the water $($n$2=1\mathrm{.}30).$

a$)$ If you are looking straight down from an airplane, while the Sun is overhead, at a region of the

slick where its thickness is $460$ nm$,$ for which wavelength$($s$)$ of visible light is the reflection

brightest because of constructive interference?

b$)$ If you are scuba diving directly under this same region of the slick, for which wavelength$($s$)$ of

visible light is the transmitted intensity strongest $($i$.$e$.$ the reflection is minimal$)?$