$h = \dfrac{p}{\gamma}$
(a) The liquid is water
$h = \dfrac{68.95}{9.81}$
$h = 7.03 \, \text{m}$ answer
(b) The liquid is oil (sp gr = 0.85)
$h = \dfrac{68.95}{0.85(9.81)}$
$h = 8.27 \, \text{m}$ answer
(c) The liquid is mercury (sp gr = 13.6)
$h = \dfrac{68.95}{13.6(9.81)}$
$h = 0.5168 \, \text{m}$ answer
(d) The liquid is brine (sp gr = 1.15)
$h = \dfrac{68.95}{1.15(9.81)}$
$h = 6.11 \, \text{m}$ answer