Thermodynamics questions $9)$ A certain gas is compressed hyperbolically to a volume of $30$ m$3.$ If the final pressure of the gas is $730$ kPa gauge, and the initial volume was $90$ m$3,$ what was the initial absolute pressure? $(4)$

$10)$ A perfect gas occupies $60$ m$3$ at $25\backslash$deg C$.$ What volume will it occupy at $-20\backslash$deg C if the pressure remains constant? $(4)$

$11)$ Calculate the required inner diameter of a spherical tank that can store $400$ kg of methane at $40\backslash$deg C and $19$ MPa $(4)$