Unutterably Silly Quiz

In looking at Paul's proposed solution he would require a total of nine races. The five races [first round] to race all horses. Select top three from each of the first races to compete in three second round races. One more race to determine the second and third fastest horse. So his total number of races is nine, not eight. There is still a solution that requires fewer than eight races total though. Paul is onto the crucial logic, he just has not made the most possible out of it. Let's see what Paul or anyone else can come up with over the next 12 hours or so.

[pdurrant]

Originally Posted by Hamlet53

In looking at Paul's proposed solution he would require a total of nine races. The five races [first round] to race all horses. Select top three from each of the first races to compete in three second round races. One more race to determine the second and third fastest horse. So his total number of races is nine, not eight. There is still a solution that requires fewer than eight races total though. Paul is onto the crucial logic, he just has not made the most possible out of it. Let's see what Paul or anyone else can come up with over the next 12 hours or so.

Sorry for my arithmetic failure!

I think the answer must be 7. Five races initially, then a race of all the winners to get the fastest horse overall.

I'll have a think this evening about how to sort out the second and third fastest with just one more race.

Unless someone beats me to it!

So it has been 24 hours since I posed the question and aside from one try by pdurrant there has been no other attempts. So here is my suggestion. I have posted my solution enclosed in spoiler tags so anyone who wishes to can continue to try and work out a solution. That and I would not want anyone sticking needles into their eyeballs for having to just look at the solution, especially not a member as venerable as Stitchawl.

Spoiler:

I come up with a minimum of seven races needed.

Preliminary round. Race all 25 horses, five horses in five races. Then for a second round run the five winners of each first round race against each other.

The winner of this sixth race is obviously the fastest horse overall. (First place in its first round race and faster than all the winners from the other first round races). Also the second place finisher in his first round race is possibly the second fastest horse overall. Similarly the third place winner from his first round race is possibly the third fastest horse overall. Drop all other horses from his first round race.

The second place horse in the sixth race is possibly the second fastest horse overall. Also the second place finisher in his first round race is possibly the third fastest horse overall. Drop all other horses from his first round race.

The third place horse in the sixth race is possibly the third fastest horse overall. Drop all other horses from his first round race.

Drop the fourth and fifth horses in the sixth race and all other horses from the first round races for these two horses.


New pool contains six horses. Already know the fastest horse (winner of second round), so run third round race among the remaining five to establish second and third fastest horses overall.

Also the floor is open for a new quiz.

[HomeInMyShoes]

I'll make him look. Without reading the spoiler,

If I do five races of five horses as follows:
A1 A2 A3 A4 A5
B1 B2 B3 B4 B5
C1 C2 C3 C4 C5
D1 D2 D3 D4 D5
E1 E2 E3 E4 E5

Then I know that all the 4th and 5th finishers are not in the three fastest. So I have the following left:
A1 A2 A3
B1 B2 B3
C1 C2 C3
D1 D2 D3
E1 E2 E3

If I race the winners and get
A1 B1 C1 D1 E1 as the finishing then all of E is dead and all of D is dead and all of the ones behind C1 are dead as well, leaving me with

A1 A2 A3
B1 B2 B3
C1

I know A1 is the fastest so I have
A1 ? ?

A2 A3
B1 B2 B3
C1

I just need to figure out if I know anything else. A1 was faster than B1, but if B1 is the second fastest than B3 cannot be, and if B1 isn't the second fastest than B2 and B3 are both dead. So toss B3 out and I can race the rest to determine second and third.

Here is the final race (race number 7) and the winner and runner up are second and third fastest.

A2 A3 B1 B2 C1

7 races.

[HomeInMyShoes]

Someone else can ask the question though as I am busy.

[Stitchawl]

John has two sisters and two brothers. Three of the five children in the family have dark brown hair, one has red hair, and one has light brown hair. Around 40% of cats with white fur and blue eyes are deaf. Using no other information, calculate the declining mass of the sun and to the nearest million years, when it will reach Supernova.



Stitchawl

[Bookpossum]

The middle of next week?

[pdurrant]

Originally Posted by Stitchawl

John has two sisters and two brothers. Three of the five children in the family have dark brown hair, one has red hair, and one has light brown hair. Around 40% of cats with white fur and blue eyes are deaf. Using no other information, calculate the declining mass of the sun and to the nearest million years, when it will reach Supernova.

Since John and his family are part of a species that have evolved sufficiently to domesticate and breed cats that have such a significant defect from a survival point of view, they must live on a planet that has been around for about 4.5 billion years circling a G-type sun. It's well known that such suns lose mass at a rate of about 4 million tons per second.

To the nearest million years never is when the sun will reach Supernova, since clearly the Sun does not have sufficient mass to do so.

It will run out of hydrogen in about another 5.5 billion years, becoming a red giant. About 3.5 billion years after that, it will become a white dwarf star.

John and his sisters ands brothers and their cats will, of course, be dead by then.

[HomeInMyShoes]

Are we sure John lives on a planet where domestic cats have no natural predators?

[red_phoenix]

Where did it say the cats are domesticated?

[pdurrant]

How did we play rock, paper, scissors before paper was invented?

[HomeInMyShoes]

Rock, paper, tree bark?

[Bilbo1967]

Originally Posted by pdurrant

How did we play rock, paper, scissors before paper was invented?

We didn't.

[Kumabjorn]

I would obviously need to check it, but I feel reasonably confident that paper predates scissors.

[Bilbo1967]

Originally Posted by Kumabjorn

I would obviously need to check it, but I feel reasonably confident that paper predates scissors.

And rocks...no....wait...probably not rocks