Pressure difference between oil pipe and water pipe is measured by a double fluid manometer as shown in Fig. For a given fluid heights and SG$,$ calculate the pressure difference $P=P_B-P_A$

$29\mathrm{.}2$kPa

$29\mathrm{.}2$ Pa

$20\mathrm{.}8$kPa

$20\mathrm{.}8Pa$