How do you prove this with only what you are given

Dropping less than two inches per mile after emerging from the mountains, a river drains into the ocean. one day's discharge at its mouth, 5.6 trillion gallons, could supply all of country a's households for seven months. based on this statement, determine how much water an average household uses each month. assume that there are 100 million households in country a. country a uses approximately nothing gallons per household per month.

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.

Is there an x intercept in the equation 60*1.15^x