Answer:

Step-by-step explanation:
Water is being pumped into an inflated rubber sphere at a constant rate of 0.03 cubic meters per second.
So, dV/dt = 0.03.
We want to show that dS/dt is directly proportional to 1/r.
In other words, we want to establish the relationship that dS/dt = k(1/r), where k is some constant.
First, the volume of a sphere V is given by:

Therefore:

Next, the surface area of a sphere S is given by:

Therefore:

We can divide both sides by 2:

We can substitute this into dV/dt. Rewriting:

So:

Since dV/dt = 0.03 or 3/100:

Therefore:

Where k = 3/50.
And we have shown that dS/dt is directly proportional to 1/r.
9/18 or 50% if you toss the coin because when you toss 1 coin you get a 1/2 chance of getting tails. Do that nine times and you get 9/18
Answer:
I think it goes like this : 20:4=5 so there's five monsters in the room
Step-by-step explanation:
if that's the case of this question it should go like this:
9(rooms)×5(monsters per room)= 45 monsters
30(monsters):5(monsters per room)=6 rooms
13(rooms)×5(monsters per room)=65 monsters
35(monsters):5(monsters per room)=7 rooms
I hope you do well in your assignment.
I hope I helped at least a little!
I think it is the 3rd one but I might be wrong...