Much or many? 1) There is too water in the bath.

1)There is too much water in the bath. 2)How many brothers and sisters do you have? 3)I dont receive many letters nowadays. 4)How much rice do you eat per week? 5)I put too much salt in the soup. 6)How many people were in you house last night ? 7)I dont have much time. 8)She didnt ask many questions. 9)My grandfather does not have much hair, anymore. 10)How many plates do we need?

Much употребляется с неисчисляемыми существительными, many - только с вычисляемыми существительными.