How do you find the function to a problem quickly?

For example: A tennis club holds a doubles tournament every spring. This year the club has 40 teams involved. At the end of each round half of the teams are eliminated. How many rounds must be played to determine the winner?

So, I already found the answer (6 rounds). How do I find its function or equation to solve?

wouldn't it just be 40^1/2 that's 6.32 so 6 rounds

But...

The table is like this
x=Number of the round
y=Teams in the round

X Y
1 40
2 20
3 10
4 5
5 2.5
6 1.25 -> 1

How do I find the function or equation using variables x and y?
(To find the function more faster because, I have 3 other problems like this and I want to try to do the others on my own.)

Well This is what I did to get 40^.5 you know the amount Y and then you already know the function X its Y^x.

that's what I just went over today in class

The number of rounds is the smallest integer n that satisfies

N*(1/2)^n = 1
where N is the number of teams.
for n = 5, 40*(1/2)^5 = 1.25
for n = 6, 40*(1/2)^6 = 0.625
So n is the answer.

It has nothing to do with square roots, as the previous answer suggests.

Thanks! (;

n=6 rounds are needed, including the championship. With 40 teams, there can be a lot of "byes" in early rounds. Up to 64 teams could be included in a 6-round tournament.

Also how did u find its function easily? Everytime I try to find the function it takes me a super long smount of time.

what is the surface area of a rectangular prism with a base area 15m2, height 3m, and lateral area 18m2?? This is my question !!! PLEAS ANSWER

To find the function or equation that represents the number of rounds needed to determine the winner in this doubles tournament, you can analyze the problem step by step.

First, let's consider the initial number of teams. In this case, we start with 40 teams.

Next, we can observe that after each round, half of the teams are eliminated. This reduction by half is a key factor in determining the number of rounds needed.

To express this mathematically, you can create an equation or function based on the number of teams remaining after each round. Let's call the number of teams remaining after each round "T".

After the first round, half of the teams are eliminated, leaving us with T = 40/2 = 20 teams.

After the second round, half of the remaining 20 teams are eliminated, leaving us with T = 20/2 = 10 teams.

After the third round, half of the remaining 10 teams are eliminated, leaving us with T = 10/2 = 5 teams.

As you can see, the number of teams remaining is halved after each round. This pattern continues until we have only one team left, which is the winning team.

Now, let's turn this into a mathematical expression. Starting with the initial number of teams (40), we need to divide it by 2 for each round. The number of rounds (R) can be represented as:

T = 40 / 2^R

Where R represents the number of rounds being played and T represents the number of teams remaining after R rounds.

For example, when T reaches 1, it means all other teams have been eliminated, and we have found the winner. In this case, we can substitute T = 1 into the equation and solve for R:

1 = 40 / 2^R

To isolate R, we can multiply both sides by 2^R:

2^R = 40

Taking the logarithm of both sides (base 2):

log2(2^R) = log2(40)

R * log2(2) = log2(40)

R * 1 = log2(40)

R = log2(40)

Using a calculator, you can approximate log2(40) as approximately 5.32. Therefore, the number of rounds needed to determine the winner is 6, as rounding up to the nearest whole number.

So, the function or equation that represents the number of rounds needed is:

T = 40 / 2^R

where T represents the number of teams remaining after R rounds, and R is the number of rounds played.