Air at standard atmospheric pressure $(1$ atm$)$ with a dry bulb temperature of $30\backslash$deg C and a wet bulb temperature of $20\backslash$deg C is first heated in a heater to a dry bulb temperature of $90\backslash$deg C$.$ Then it is passed through a bed of apricot slices to dry them. The air existing from the bed is at a dry bulb temperature of $60\backslash$deg C$.$ It is then passed through a dehumidifier to reduce its relative humidity to $15\%,$ with the dry bulb temperature remaining constant during this process.

determine $($a$)$ the amount of moisture removed from the bed per kg of dry air and $($b$)$ the amount of moisture removed in the dehumidifier per kg of dry air.