Consider a U$-$tube whose arms are open to the atmosphere. Now water is poured into the U $-$

tube from one arm and light oil with density $809k\frac{g}{m^3}$ from the other. One arm contains

$70$ cm high water, while the other arm contains both fluids, with an oil$-$to$-$water height ratio of

$6\mathrm{.}7.$ Determine the height of oil column in the arm in cm $.$ Take the density of water as $1000$

$57\mathrm{.}27$