A container contains a liquid with refractive index of 1.2 up to a height of 60 cm and another liquid having refractive index 1.6 is added to height…

A container contains a liquid with refractive index of $\displaystyle 1.2$ up to a height of $\displaystyle 60$ cm and another liquid having refractive index $\displaystyle 1.6$ is added to height H above first liquid. If viewed from above, the apparent shift in the position of bottom of container is $\displaystyle 40$ cm. The value of H is $\displaystyle \_\_\_\_$ cm . (Consider liquids are immisible)