Refractive index of water with respect to air is 1.33, refractive index of oil with respect to water is 1.45 and that of glass with respect to oil is 0.78. What is the refractive index of glass with respect to air?

Explanation

`"Here" " "a^(mu)w = 1.33, w^(mu)o = 1.45, o^(mu)g = 0.78`
`"We know" " " a^(mu)w xx w^(mu)o xx o^(mu)g xx g^(mu)a = 1`
`or, " " a^(mu)w xx w^(mu)o xx o^(mu)g = (1)/(g^(mu)a) = a^(mu)g`
`or, " " 1.33 xx 1.45 xx 0.78 = a^(mu)g`
`or, " " a^(mu)g = 1.5`