Which of the following is NOT an arithmetic sequence? a
1, 2, 3, 4,...
b
0.25, 0.5, 0.75, 1, ...
c
2, 2.5, 3, 3.5,...
d
-2, 4, -6, 8,...

D

Step-by-step explanation:

To be an arithmetic sequence, the numbers have to be added or subtracted by a constant number. D is not the answer because -2+6 equals 4, but 4+6 doesn't equal -6, so D cannot be a arithmetic sequence.

how long did the flood last

step-by-step explanation:

then i will answer

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.