Skip to main content

Coin Flipping Puzzle: Interview Question

Golu has 100 identical coins (with head side and tail side) which he wants to donate to someone. There are many people who are aiming to get this collection of 100 coins. So Golu created a puzzle using all 100 coins and declared that the one who will solve his puzzle will get all the coins. You desperately need money so solving the puzzle is only option you have.

The Problem goes like this:
All 100 coins are laying flat on a table. 80 of them are heads up and remaining 20 are tails up. You can’t feel, see or in any other way find out which side is up. Split the coins into two piles(sets) such that there are the same number of tails in each pile.
[Baby Hint]: If number of coins in first pile is n then other pile will have 100-n coins.



First try yourself before peeking into the solution below. 




Solution:

Solution is very easy. Divide the pile of 100 coins into two separate piles of 80 and 20 coins respectively. Just flip every coin of the pile of 20 coins and you will have same number of tails up(also same number of heads) in both piles.

Too easy to digest, huh. Let’s see mathematically what’s happening. You have just divided 100 coins into two piles of 20 and 80 coins each. Since you can’t see so you have no idea how many tails/heads up are there in two piles. Let’s assume that the number of tails up in first pile(20 coins pile) is X then number of heads up coins would be 20 - X. Since, initially total number of tails up coins was 20 so number of tails up coins in second pile(80 coins pile) would be 20 - X. If you flip every coin of first pile then all X tails up coins will become heads up and remaining 20 - X heads up coins will be now tails up. Second pile is already having 20 - X tails up coins so we have now equal number of tails up coins in both piles. And since they have equal number of tails up coins means they also have same number of heads up coins. Easy right!!

Comments

  1. The first thing you’ll discover when accessing El Royale is the trendy animations and bonuses floating around the corners. This fashionable and fashionable web site is the primary one on our record with an lively social media presence on each Facebook and Twitter. Increased social media presence means extra accountability and the chance to publicly work together with the casino and engage in a extra personal relationship. As a general rule, the bigger the bonus, the extra times it will have to be rolled over. It will depend 점보카지노 on the casino, and extra doubtless depend on the value of the bonus received. Take the bonus that requires the least monetary value turnover for one of the best likelihood of turning it into actual cash.

    ReplyDelete

Post a Comment

Popular posts from this blog

Krishna ki chetawani -- कृष्ण की चेतावनी

कृष्ण की चेतावनी -- रामधारी सिंह दिनकर  वर्षों तक वन में घूम घूम बाधा विघ्नों को चूम चूम सह धूप घाम पानी पत्थर पांडव आये कुछ और निखर सौभाग्य न सब दिन सोता है देखें आगे क्या होता है मैत्री की राह दिखाने को सब को सुमार्ग पर लाने को दुर्योधन को समझाने को भीषण विध्वंस बचाने को भगवान हस्तिनापुर आए पांडव का संदेशा लाये दो न्याय अगर तो आधा दो पर इसमें भी यदि बाधा हो तो दे दो केवल पाँच ग्राम रखो अपनी धरती तमाम हम वहीँ खुशी से खायेंगे परिजन पे असी ना उठाएंगे दुर्योधन वह भी दे ना सका आशीष समाज की ले न सका उलटे हरि को बाँधने चला जो था असाध्य साधने चला जब नाश मनुज पर छाता है पहले विवेक मर जाता है हरि ने भीषण हुँकार किया अपना स्वरूप विस्तार किया डगमग डगमग दिग्गज डोले भगवान कुपित हो कर बोले जंजीर बढ़ा कर साध मुझे हां हां दुर्योधन बाँध मुझे ये देख गगन मुझमे लय है ये देख पवन मुझमे लय है मुझमे विलीन झंकार सकल मुझमे लय है संसार सकल अमरत्व फूलता है मुझमे संहार झूलता है मुझमे उदयाचल मेरा दीप्त भाल, भूमंडल वक्षस्थल विशाल, भुज परिधि-बन्ध को घेरे हैं, मैनाक-मेरु पग मेरे हैं। दिपते जो ग्रह नक्षत्र निकर, सब हैं

आ तमाशा तू भी देख

देखने वाले देखते हैं, सब कुछ देखते हैं ये लोग देख देख कुछ करते नहीं, जाने कहाँ से लगा ये रोग ।  गरीब देखा, पीड़ित देखा, देखे उनके खेत बंजर फर्क उनको कुछ पड़ा नहीं, देख किसानों का ये मंजर झूठ वादा, झूठे काम, किसानों के प्रति झूठा सम्मान सब देख मंद मुस्काते हैं, चाहे फांद गला लटके किसान हिन्दू देखा, मुस्लिम देखा, देखी जाने कितनी जाती पर जिससे इंसान दिखें, ऐसी कला कहाँ उनको आती देखने वाले देखते हैं, सब कुछ देखते हैं ये लोग देख देख कुछ करते नहीं, जाने कहाँ से लगा ये रोग ।  घर में देखा, ऑफिस में देखा, देखा ओलंपिक्स में परचम लहराते चाहे जितने हुनर उनके देखे, पर कसी फब्तियां आते जाते कल के दुश्मन आज हैं भाई, गले पड़े भुला के सब लफड़े लेकर ठेका आदर्शवाद का, नाप रहे दूजों के कपडे अधरों पे बेशर्मी का पर्दा, जो पीड़ित है उसी की गलती देख देख इन बड़बोलों को, दानवों की कमी कहाँ है खलती देखने वाले देखते हैं, सब कुछ देखते हैं ये लोग देख देख कुछ करते नहीं, जाने कहाँ से लगा ये रोग ।  सड़क नहीं, बिजली नहीं, जनता का पैसा, उनकी जेब जहाँ देखो वहीँ मिलेंगे, भरे प

कोई तो होता

भटकता जब मैं अपना पथ  भूल जाता लगाकर मैं गोता, वापस मुझको लाने वाला  काश ऐसा कोई तो होता।  गिरकर, भटककर, खाकर चोट  जब मैं मन ही मन रोता,  मेरे दुखों को समझने वाला  काश ऐसा कोई तो होता।  सन्नाटे के धुंध में जब  चुप चुप अकेले मैं सोता,  मुझसे बातें करने वाला काश ऐसा कोई तो होता।  अनगिनत जिम्मेदारियां अपनी  होकर असहाय जब मैं ढोता, मुझको सहारा देने वाला  काश ऐसा कोई तो होता।  जीवन के संघर्षों से लड़कर  जब मैं अपना मनोबल खोता, साहस मुझे बंधाने वाला  काश ऐसा कोई तो होता।  खाकर अपने पीठ पे खंजर  जब मैं अपने जख्मों को धोता,  मरहम मुझको करने वाला काश ऐसा कोई तो होता। -- शशिकांत  * उपरोक्त पंक्तियाँ मेरी पुस्तक " आ तमाशा तू भी देख " का अंश हैं।

JSON vs YAML

JSON JSON(JavaScript Object Notation) is a human-readable data exchange format.  JSON is built on two structures: A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array. An ordered list of values. In most languages, this is realized as an array, vector, list, or sequence. JSON's basic data types are: Number : a signed decimal number that may contain a fractional part and may use exponential E notation, but cannot include non-numbers such as NaN. The format makes no distinction between integer and floating-point. JavaScript uses a double-precision floating-point format for all its numeric values, but other languages implementing JSON may encode numbers differently. String : a sequence of zero or more Unicode characters. Strings are delimited with double-quotation marks and support a backslash escaping syntax. Boolean : either of the values true or false Arra

[Fixed] Alexa can count only from 1 to 10

Note : At the time of writing this post, Alexa had this issue which has been resolved. Alexa can now count flawlessley even in reverse. Alexa is the smart virtual assistance by Amazon. It is beating google now and Siri on non-screen devices. Alexa is hailed for its intelligence but it seems that the Alexa knows to count only from 1 to 10. By 1 to 10, I mean exactly from 1 to 10; neither more nor less. Even asking Alexa to count from 1 to 5 or 3 to 10 or 3 to 5 results in an apology from Alexa. Watch the above video to see for yourself.

Never compare your life to others. You have no idea what their journey is about.

 

10 basic git commands you must know

If you work on software development project then you might have already used git for version control. If you haven't used git yet then it's high time you should learn and start using this. Following are the 10 git commands you must know while getting started with git. 1.  git init :  It initializes the git repository. Running this command creates a directory(. git ) inside the current directory which contains git configuration and other repository data.  See below image how there was no git repository initially and after running git init , an empty git repository is initialized as we can see the .git directory gets created. 2. git status : It shows the current status of the repository by showing the difference between index file and the current HEAD commit. It shows the untracked files and files which are added to staging area but not yet committed. You can use different options with git status .  Using -s option gives the output in short format. Option -v or --

Close up images of US Dollar bill of $10

 

Get access to everyone's Aadhaar data at Rs 500--A Tribune Report

Time and again UDAI(Unique Identification Authority of India) has been asserting that our Aadhaar data is secure and people of India can rest assured about the protection of our personal and biometric data. We have seen security flaws surfacing on the Internet over alleged data breach of Aadhaar and again Tribune has published about the existence of major security breach happening on daily basis. Our Aadhaar data, which is supposed to be highly secure in the hands of UIDAI is available to anyone who can pay Rs. 500. According to Tribune, people are approached via WhatsApp for the service using which you are provided the portal and the username & password to use the portal. Using this service you can feed Aadhaar number and you will be able to download all personal details. This service is being provided at the mere amount of Rs. 500. Not only this, if you pay Rs. 300 more, you will be able to download the Aadhaar card also. The government of India is trying to make Aadhaa