Question

calculate the speed of light in water of refractive index 4/3.(given C= 3×10^8m/s)

Answer 1

refractive Index =speed of light in vacuum(c)/speed of light in water
=>
$\frac{4}{3} = 3 \times {10}^{8 } \div a \:$
=> a is speed of light in water is
$9 \times {10}^{8} \div 4$
=>
speed of light in water
$2.25 \times {10}^{8}$
Hope it helps you...

Answer 2

refractive index =c/v
4/3=c/3*10^8
c=12*10^8/3
c=4*10^8