Question

The refractive index of water of kerosene , turpentine and water are 1.44 , 1.47,1.33 respectively . In which of these materials does light travel fastest and slowest?

Answer 1

Hello !
More the Refractive index less is the speed of light travelling in that medium.
So, the relation between the speed of light in Kerosene , Turpentine and Water is 
Water >Kerosene>Turpentine
See, more refractive index means more loss in the energy and more the deviation i.e. the photons lose out their energy and they change their wavelength but frequency remains constant .
I hope u r satisfied 
Thank you !

Answer 2

$</p><p>lesser \:the \:refractive\:index\:increase\:the\:speed \:of \:light\:in\: the</p><p></p><p></p><p> \;medium\: because \: refractive\: index\: is\: directly\: proportional\:to</p><p></p><p></p><p>\; refractive density.</p><p></p><p>\;and\:Ur\:answer\:is\:Water$