Examples $3$a and $3$b$.$

$($a$)$ Convert a pressure head of $4\mathrm{.}60$ m of water to meters of oil, sp gr $0\mathrm{.}750.$

$($b$)$ Convert a pressure head of $24$ in of mercury to feet of oil, sp gr $0\mathrm{.}750$

PLEASE WRITE OUT SOLUTION VERY CLEARLY AND ON PAPER $.$