Puzzles and aptitude problem

Why add puzzles and logical problem in a Data Science course?

Well, because you are supposed to solve problems of the same intensity on the floor.
Well, because you need to chisel your logic every now and then.
Well, because these are asked in the hiring interviews 😛
Well, because you can’t run away from Mathematics in a domain which is closer to it that it appears.

1. When one of my friends was asked the following question in the last round of WNS Global Services

“Tell me different ways in which you can tell me if the light inside glows after you shut the door”

2. A classic beaker and bucket challenge is always on the cards. There are two beakers, 4 liters and 5 liters, and a bucket. Get me 7 liters of water in the bucket.

Don’t directly jump to the answer, yeahh..close your eyes and think about a solution. In an interview, you will not get more than 2 minutes for this problem.

3. Make 120 using 5 zeroes. You can use any mathematical operator

4. Now make it using 4 zeroes.

5. There are two kids, and you have a cup of coffee. How will you divide it into two cups so that both the kids are satisfied?

6. Using 3 cuts, divide a cake into 8 parts

7. Suggest me one more way. Equal means equal, you need to give cream and base equally to all the 8 parts.

8. Use only 4 weights to make a device which can measure the following weight:-
a. up to 15 kgs
b. up to 40 kgs
c. up to 80 kgs

9. You are given two candles of equal size, which can burn 1 hour each. You have to measure 45 minutes with these candles.

10. One last question in this interview, What will be the name of the third person who you will meet today?

For the aptitude part, all we can suggest is that you solve problems on the following topics from any online resource:
1. Time, Speed, and Distance
2. Probability
3. Permutation and Combination
4. Try solving Sudoku
5. Work and Time
6. Guesstimate

Puzzle answers:-
1. a. Keep a video recorder inside the fridge
b. Keep a radium inside the fridge for a couple of hours. If it glows after two hours, then the light was on, else off

2. Take the 5-liter beaker and fill it completely, pour the water in the 4-liter beaker. You are left with 1 liter water, pour it in the bucket. Repeat it again to get 2 liter water in the bucket.

Now fill the 5 liter beaker and put it in the bucket.

7 done !!

– (0!+0!+0!+0!+0!)!


-A logical question with a tinge of pun in it. Ask one of the kid to divide and the second one to choose 😛

– Two cuts at the right angle and the third one directly between the top and the base will get you 8 parts. The lucky 4 will get the cream 😛

-Two cuts at the right angle and then put the parts on each other and strike the third cut right on the middle. You get 8 pieces, all equal

a. up to 15 kgs – 1 kg, 2 kg, 4 kg, 8kg
b. up to 40 kgs – 1 kg, 3 kg, 9 kg, 27 kg
c. up to 80 kgs – 2 kg, 6 kg, 18 kg, 54 kg

If the weight is less than 2 kgs, it is 1 kg.
If it is more, put 6kg on one side, your item and 2kg on the other. If item and 2kg are less then 6kg, the item is 3kg. 
If it is more, put 6kg on one side, your item on the other. If the item is less then 6kg, it’s 5kg….so on

Keep both the candles side by side. First light just one candle, when you see that the first candle is exactly half the height of the second, light the second candle (which is when 30 minutes are up). The second candle will then burn for one hour and you’ll be able to clock 90 minutes

Pappu Yadav or any random name, The interviewer can’t ask you to defend the answer as it was the last question. Don’t fall for any stupid question if the interviewer specifies that it is the last question

Candidates with average aptitude are subject to rejection, so read this part carefully before applying to jobs.

If and only if you want to practice more interview puzzles, then do try this book out 100 Puzzles and Case Studies to Crack Data Science interview

Keep practicing 🙂


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