What is the average rate, in m/s, at which these 6 dolphins swam during this observation? i know the answer is 64 but i wanna know how to do it.

You would just add up all of the values and divide by six to get the average

Total Distance = (40 x 10) + (60 x 20) + (30 x 20) + (90 x 30) + (50 x 30) + (80 x 40) = 9600 m

Total time = 10 + 20 + 20 + 30 + 30 + 40 = 150 sec

Average = 9600 ÷ 150 = 64m/s

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64m/s

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.