Mathathon Sample Question 3

Logic Level 2

You must take two different tablets (A and B) each day.

If you forget one, or take more than one of any type, you will get sick.

Unfortunately they look exactly the same, and to make matters worse, with only two days supply left, you drop all 4 tablets on the kitchen floor together!

W h a t c a n y o u d o ? What \ can \ you \ do?

(PS - If you're cutting a tablet, you are taking only one of its halves, which means that if you cut an A and a B tablet into halves, you're taking an A half and a B half)

Take 1 tablet and cut the rest into halves, then take 2 halves. You will definitely get sick. Take 2 random tablets. Cut each tablet in half, and take 4 halves.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

6 solutions

David Hairston
Jul 2, 2020

* Pretend you are color blind! *

I like your animation!

Rajam Arunprakash - 11 months, 2 weeks ago
Lam King Fung
Jul 2, 2020

Didn't came up with a clear explanation for "Cut each tablet in half, and take 4 halves." But I've used excel to visualize the outcome for other options. \\ First, you will not get sick for sure as scenario of taking the right combination of pills are here. \\ For "Take 1 tablet and cut the rest into halves, then take 2 halves." \\ \\ For this option, I've only listed the possibility of taking one of the A pills as the table will be similar for other pill. \\ For "Take 2 random tablets." \\ \\ (Typo in the picture. the probability should be 0.33) Forgive me for using a dumb way to solve it.

Awesome solution! NOt dumb at all!

A Former Brilliant Member - 11 months, 2 weeks ago

A very good analysis.

Akela Chana - 11 months, 2 weeks ago
Ved Pradhan
Jul 2, 2020

This is a well known logic puzzle.

We know that each day, you must eat one A A pill and one B B pill. With two days of supply, you therefore have two A A pills and two B B pills.

When you drop them on the floor, you don't know which order they are in, but that doesn't matter! The key thing to realize is that if you take whole pills, there's a chance you could be taking more than one pill for one of the types and none for the other type. Because of that, we can't take a whole pill.

However, if we use the fact that none of the pills are a mix of A A and B B , taking half of each pill will gives us in some order: 1 2 A + 1 2 A + 1 2 B + 1 2 B = A + B \frac{1}{2}A+\frac{1}{2}A+\frac{1}{2}B+\frac{1}{2}B=A+B . Thus, we got our desired amount! It helps to visualize things, so here is a picture.

One more thing. It's very easy to keep track of which pill was broken in half and which isn't yet broken. You can feel it in your hands. Thus, there's no chance of overconsumption.

Awesome solution!

A Former Brilliant Member - 11 months, 2 weeks ago

Log in to reply

Thanks, @Percy Jackson !

Ved Pradhan - 11 months, 2 weeks ago

Good solution, yes this is a well known puzzle.

Akela Chana - 11 months, 2 weeks ago
Akela Chana
Jul 2, 2020

Not A MATHEMATICAL solution.

Options 2 and 3 is out of consideration.

Process of Elimination still counts as math (logic is a subset of math), so this is technically a mathematical solution. Awesome solution!

Ved Pradhan - 11 months, 2 weeks ago

Thanks for encouragement @Ved Pradhan

Akela Chana - 11 months, 2 weeks ago
Vishruth K
Mar 30, 2021

I thought about the problem and chose Cut each tablet in half, and take 4 halves as my answer. I got it right.

Everybody, here's a super easy Bonus - How do you know which tablets are cut and which ones aren't? Comment your answers below.

I won't eat. I am not sick. Problem solved.

Vinayak Srivastava - 11 months, 2 weeks ago

Log in to reply

LOL XD, but Jokes Apart, that's not the correct answer.

A Former Brilliant Member - 11 months, 2 weeks ago

Log in to reply

I chose incorrect answer only :)

Vinayak Srivastava - 11 months, 2 weeks ago

1 pending report

Vote up reports you agree with

×

Problem Loading...

Note Loading...

Set Loading...