Speed of light in certain medium

[songoku]

Homework Statement

Light travels at different speed through different materials. If it travels at speed c1 in a medium of refractive index 1.2, what is its speed in a medium of refractive index 1.6

a. 1.3 c1
b. 0.67 c1
c. 2 c1
d. 1.7 c1
e. 0.55 c1

Homework Equations

$$n=\frac{c}{v}$$

The Attempt at a Solution

n1 v1 = n2 v2

v2 = v1 * n1/n2 = 1.2/1.6 * c1 = 0.75 c1 ??

 

[rl.bhat]

Your answer is correct, but there is no choice!
Check the question. Whether the light is entering from air to medium in both the case?

 

[songoku]

Hi Mr. rl.bhat

That's all the question. Thanks a lot for your help