What you don't want is the value of r(t) becoming negative. Surely that would represent water escaping the reservoir.
How big can (t) get before water actually starts escaping the reservoir?
Essentially, to figure this out r(t) would have to be equal to 0.
700 - 40t = 0
40t=700
t=700/40=17.5
So the first answer is 17.5 seconds. After this amount of time has elapsed the reservoir will start to lose water as r(t) would become negative.
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The reservoir had the least amount of water in it before it was being filled. That was when t=0. The volume of water in the reservoir wasn't negatively impacted as not enough water had escaped it during the 17.5 to 30 second period.
1.A 2.D 3.B These are the answers I think is the choice to your question.
Answer:
276 Guests
Step-by-step explanation:
Calculation to determine how many guest were at the wedding
Guests that choose beef =1/3
Guests that choose chicken= 5/12
Guests that choose vegetarian=69
Now let calculate the how many guest were at the wedding
Let x represent the numbers of guest that were present at the wedding
Hence,
x/3 + 5x/12 + 69 = x
9x/12 + 69 = x
12x/12 - 9x/12 = 69
3x/12 = 69
x/4 = 69
x=69*4
x = 276 guests
Therefore the numbers of guests that were at the wedding is 276
The chance of picking a almond cookie the first time:
you have 6 cookies, 3 of them are almond
So the chance of taking an almond cookie is

The second time there are 5 cookies left, 2 of them are almond cookies
The chance of taking an almond cookie is

To know the probability of picking two almond cookies in a row, multiply the changes:

The chance of taking two almond cookies is 1/5