A crude oil with a density $900k\frac{g}{m^3}$ flows in a horizontal pipe as shown in the figure. The diameter of main oil pipeline $($pipe $1)$ is $1000mm$ and pipe $2$ is $500mm.$ If the fluid volumetric flow rate is $50,000$ litres per minute, determine the following:

$($a$)$ what will be the gauge pressure difference between point $(1)$ and $(2)$ in kPa

$($b$)$ if a gauge pressure of pipe $1$ is $10$kPa, what will be the gauge pressure in pipe $2($kPa$).$

$($a$)2\mathrm{.}39$kPa& $($b$)7\mathrm{.}61$kPa

$($a$)7\mathrm{.}61$kPa& $($b$)2\mathrm{.}39$kPa

$($a$)10$kPa& $($b$)2\mathrm{.}39$kPa

$($a$)10\mathrm{.}0$kPa& $($b$)7\mathrm{.}61$kPa