- Recommended Books
- Mind Twisters/Puzzles

I am greatly thankful to Chaitanyas Academy for helping me to direct my career in an appropriate way. Personal attention was always paid to us. The timely guidance of the teachers has been really beneficial for us. So thank you!!

– Rohan Kamble (IIT-JEE, AIEEE 166)

I attended a seminar of chaitanyas academy after my class 10 exams and came to know about the competition laid in front for engineering entrances. The extensive schedule and highly educated faculty helped me to improve to a great extent. This in turn elevated my performance. All teachers taught conceptually and also they taught to sort problems in various ways. The purpose of going to big cities for coaching can be satisfied in baramati.

– Suraj Jagtap (JEE Mains 2013)

**PHYSICS:**UNIVERSAL SELF SCORER BY UNIVERSAL BOOK DEPOT OR H.C VERMA CONCEPTS IN PHYSICS I/II**CHEMISTRY:**UNIVERSAL SELF SCORER BY UNIVERSAL BOOK DEPOT P. BAHADUR FOR NUMERICAL CHEM OR BOOKS BY O P TONDON**BIOLOGY:**NCERT, UNIVERSAL SELF SCORER BY UNIVERSAL BOOK DEPOT, TRUEMAN'S BIOLOGY OR mtg BIOLOGY BOOKS OR PRADEEP'S BIOLOGY OR DINESH BIOLOGY

**PHYSICS:**ARIHANT (DC Pandey) OR H.C VERMA CONCEPTS IN PHYSICS I/II**CHEMISTRY:**UNIVERSAL SELF SCORER BY UNIVERSAL BOOK DEPOT P. BAHADUR FOR NUMERICAL CHEM OR BOOKS BY O P TONDON**MATHS:**MTG CENGAGE (G. Tewani) JEE-ADVANCED & JEE-MAINS

This riddle is attributed to Albert Einstein and it is claimed that 98% of the people in world are incapable of solving it.

Let us assume that there are five houses of different colors next to each other on the same road. In each house lives a man of a different nationality. Every man has his favorite drink, his favorite brand of cigarettes, and keeps pets of a particular kind.

1. The Englishman lives in the red house.

2. The Swede keeps dogs.

3. The Dane drinks tea.

4. The green house is just to the left of the white one.

5. The owner of the green house drinks coffee.

6. The Pall Mall smoker keeps birds.

7. The owner of the yellow house smokes Dunhills.

8. The man in the center house drinks milk.

9. The Norwegian lives in the first house.

10. The Blend smoker has a neighbor who keeps cats.

11. The man who smokes Blue Masters drinks bier.

12. The man who keeps horses lives next to the Dunhill smoker.

13. The German smokes Prince.

14. The Norwegian lives next to the blue house.

15. The Blend smoker has a neighbor who drinks water.

Question is: Who keeps fish?

**Answer :** German

There are 4 men each wearing a either a black or a white hat. They are standing in rising water, cannot move and can only look forward. Between A and B is abrick wall which they cannot see through.

They know that between them are 4 hats of which 2 are black and 2 are white, but they do not know which colour they are wearing.

In order to stop the level of the water rising and drowning, one of them must call out correctly which colour hat he is wearing. They are not allowed to talk to each other and have 10 minutes to fathom it out.

Which one of them calls out, and how does he work out which colour he is wearing?

You have just walked into a dark two-storey house. There are three light switches on the first floor A, B and C. Only one of the switches works, and it turns on the light on the second floor.

You cannot see the second floor light from the first floor and there are no windows in the building, but you do have a flashlight.

You can only make one trip up the stairs, and you can only flip one switch at a time. How do you determine which of the three switches turns on the light on the second floor ?

You are travelling down a road to a village. You reach a fork in the road and find a pair of identical twin brothers standing there. One of the brothers always tells the truth and the other always lies.

If you are allowed to ask only one question to one of the brothers to find which is the correct road to the village, what is your question ?

**Answer :** to the Twin brothers Puzzle

Point to one of the roads in the fork and ask the following question to one of the brothers.
"If I ask your brother if this is the correct road to the village will he say yes or no?"
If he answers is "no" then it is the correct way to the village.
Think about it -

If the brother you are speaking to is the one who always lies, then he will say "no" as he knows that his brother who speaks the truth would anwser "yes". If the brother you are speaking to is the one who speaks the truth, he will say "no" as he knows that his brother will lie about it being the correct road. Either way an answer "no" tells you it is actually the right road. Similarly if you are pointing to the wrong road you will get the answer "yes".

A bottle of wine cost £10. The wine was worth £9 more than the bottle.
How much was the bottle worth?

**Answer :** to the Bottle of Wine Puzzle

A common wrong answer is £1. Now, if the bottle were really worth a £1, then the wine, being worth £9 more than the bottle, would be worth £10. Hence the wine and bottle together would be worth £11.

The correct answer is that the bottle is worth 50 pence and the wine is worth £9.50. Then the two add up to £10.

A boat has a ladder that has six rungs, each rung is one foot apart. The bottom rung is one foot from the water. The tide rises at 12 inches every 15 minutes. High tide peaks in one hour.
When the tide is at its highest, how many rungs are under water?

**Answer :** to the Ladder Puzzle
None, the boat rises with the tide.

You have two buckets - one holds exactly 5 gallons and the other 3 gallons
How can you measure out 4 gallons of water into the 5 gallon bucket ?

(Assume that you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

**Answer :** to the 4 gallon Bucket Puzzle

Here is a solution:

1) Fill the 3-gallon bucket, dump it into the 5-gallon bucket

2) Fill the 3-gallon bucket, fill the 5-gallon, leaving 1 gallon left in the 3-gallon bucket

3) Empty the 5-gallon bucket

4) Dump the 1 gallon from the 3-gallon bucket into the 5-gallon bucket

5) Dump one full bucket from the 3-gallon bucket on top of the 1 gallon in the 5-gallon bucket

You're left with four gallons of water in the 5-gallon bucket.

Two MIT math grads bump into each other at Fairway on the upper west side. They haven’t seen each other in over 20 years.

THE FIRST GRAD SAYS TO THE SECOND: “how have you been?”

SECOND: “great! i got married and i have three daughters now”

FIRST: “really? how old are they?”

SECOND: “well, the product of their ages is 72, and the sum of their ages is the same as the number on that building over there..”

FIRST: “right, ok.. oh wait.. hmm, i still don’t know”

SECOND: “oh sorry, the oldest one just started to play the piano”

FIRST: “wonderful! my oldest is the same age!”

problem: how old are the daughters?

Camel and 30000 bananas

A men want to cross a desert with a camel and 3000 bananas,desert is of 1000kms long.At once camel can take 1000 bananas. For each one km to walk camel eats 1 banana. How many bananas can the men able to cross other side of desert with the help of camel.

**Answer :** 533.33 bananas