$10$ kg of a food material containing $80\%$ of moisture will be dried using dey ait, an $75\backslash$deg C under $1$ atm pressure Used air will leave the dryer with $70\%$ relative humidity If $2$ kg of moisture will be removed from the food material in one hour

$,$a$)$ Calculate feeding rate of dry air $($m$^3/$h$)?$

b$)$ Calculate moisture content $(\%)$ of food after one hour?