Changes in the depth of a river day week one week two monday rose 7 inches rose 5 inches tuesday fell 4 inches rose 1 inch wednesday fell 5 inches fell 6 inches thursday fell 3 inches fell 9 inches friday rose 2 inches fell 7 inches saturday rose 6 inches fell 2 inches sunday rose 8 inches rose 4 inches the table shows how the depth of a river changed each day for the last two weeks. what happened to the depth of the river over the two weeks? a) it fell 3 inches. b) it fell 5 inches. c) it fell 7 inches. eliminate d) it rose 3 inches. e) it rose 5 inches.

the answer is A, this was the correct answer on usatestprep

Step-by-step explanation:

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.