Please help I need to finish this test today

The green family is a family of six people. they have used 4,885.78 gallons of water so far this month. they cannot exceed 9,750.05 gallons per month during drought season. write an inequality to show how much water just one member of the family can use for the remainder of the month, assuming each family member uses the same amount of water every month.

Ill mark the brainliest if you me with the these three questions 7,8,9

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?