## How many golf balls will be heard into the school bus?

For reference, the National Transport Vehicle Standards for Schools in the USA for 1995 indicate the maximum size of a school bus – 40 feet long and 8.5 feet wide. The standard diameter of a golf ball is 1.69 inches with a tolerance of 0.005 inches.   Clearly, this task is a kind of Fermi…

## How to determine duplicate URLs?

You have a lot of URLs, about 10 billion. How would you organize an effective duplicate search? Surely, all of them cannot be stored in the memory.   The complexity of the task lies in the fact that you have 10 billions of URLs. How much storage you will need to store 10 billions of…

## A task for cryptography basics with a detailed analysis

Here is the task through which you can briefly become familiar with the basics of RSA-cryptography.   Let’s suppose you want to make sure that your friend John has your phone number. However, you cannot ask him directly. You will have to write him a message on the card and give the card to…

## The task of the country with boys and girls

Let’s imagine a country where all parents want to have a son. Each family continues to give birth to children until they have a boy and then stops. What will be the ratio of boys and girls in this country?   You should ignore the situations where twins, triplets, couples who have no children,…

## What errors can cause a C application crash

You have the source code of the application written in C, which crashes after launch. After ten starts in the debugger, you find that the application crashes each time in different places of the code. The application is single-threaded and uses only the standard C library. What errors can cause the application crashes? How…