Sludge coming form a municipal sewage treatment has to be dried before it can be

composted. If a sludge containing $80\%$ water, $20\%$ solid is passed through a dryer to

remove $90\%$ of its water content, calculate $($a$)$ the amount of water removed per ton of sludge $($b$)\%$ of water in the dried sludge. include a diagram too please. need help asap