Answer:
570 m³
Step-by-step explanation:
The volume of water is the product of flow rate of water and the time taken. We are to get the volume of water used between 6 am and 9 am, that is for 3 hours (9 - 6).
We are given the flow rate at 6 am and the flow rate at 9 am, but this flow rate changes between 6 am and 9 am. To get the estimate of the water used, Let us assume that it flows at the same flow rate as it was at 6 am throughout, hence:

Also, let us assume that it flows at the same flow rate as it was at 9 am throughout, hence:

To get the best estimate of the total volume, let us find the average of the two values, hence:

Answer:
choosing two socks from a drawer of black and white socks without replacement
Step-by-step explanation:
Dependent events have results that depend on each other. When I take one sock out, there are less socks in the drawer to pick from. The probability of picking a certain sock changes because the number of socks are different when I do not put the sock back. That makes the events dependent.
When I put the sock back, the probability goes back to what it was before I took the sock, and now the results do not depend on each other, so when they are replaced, they are independent
So if the sandwiches cost $7.75 each and the total was $113.50 that would mean that there were 14 sandwiches bought. So 14 times 7.75 is 108.50.
Use the permutation formula
nPr = (n!)/((n-r)!)
20P15 = (20!)/((20-15)!)
20P15 = (20!)/(5!)
The final answer is choice A