Correct Answer - d
Thinking Process Pressure of two points lie in the same horizontal level should be same and `p=hdg` Both ends of the U tube are open. So the pressure on both the free surface must be equal.
i.e, `p_(1) = p_(2)`
`h_("oil").S_("oil") = h_("water").S_("water").g`
`S_("oil") = "specific density of oil"`
`S_("oil") = (h_("water").S_("water").g)/(h_("oil).g)`
From figure `S_(oil) = ((65 + 65) xx 1000)/((65 + 65+10))`
`= 928 kgm^(-3)`