Wan Chai Brain Teasers & Puzzles

Brain Teasers & Puzzles

 

Can you solve all 6? (answer at the bottom).

 

1. Pouring Water Puzzle

How can you measure 6 litres of water using only 4 and 9-litre bowls?

2. Rhyme Riddle

Here’s a nursery rhyme riddle:

Little Nancy Etticoat
In her white petticoat
With a red nose
The longer she stands
The shorter she grows

Given this rhyme, what is “she?”

 

3. Solve this Mystery

There is a light bulb inside a closet. The door is closed, and you cannot see if the light is on or off through the door. However, you know the light is off to start. Outside of the closet, there are three light switches. One of the switches controls the light bulb in the closet. You can flip the switches however you want, but once you open the door, you can no longer touch the switches.

How do you figure out without a doubt which switch controls the light?

 

4. Number Sequence

What are the missing numbers in this sequence?

6 + 4 = 210
9 + 2 = 711
8 + 5 = 313
5 + 2 = 37
7 + 6 = 113
9 + 8 = 117
10 + 6 = 416
15 + 3 = 1218
?? + ?? = 123

 

5. Round Vs. Square

Why is it better for manhole covers to be round rather than square?

 

6. Riddle

There is a dead man in the middle of a field, nothing is around him and there are no footprints of any sort. There is an unopened package next to him. How did he die? HINT: As he approached the field he knew he was going to die.

 

Answers
  1. First fill the 9-litre bowl. Then pour 4 litres to the 4-litre bowl (there are 5 litres in the 9-litre bowl afterwards) and pour out the water from the 4-litre bowl. And again pour 4 litres to the 4-litre bowl and empty it. Then pour the remaining litre to the 4-litre bowl but this time keep it there. Fill the 9-litre bowl to the top for the second time and pour water to fill the 4-litre bowl to the top. Thus the required 6 litres stay in the 9-litre bowl.
  2. A candle.
  3. Flip switch number 1 and wait a few minutes. Flip switch number 1 back to its original position, and then immediately flip switch number 2. Open the door. If the light is on, then switch number 2 controls it. If the light is off, then go and feel the bulb with your hand. If the bulb is hot, the switch number 1 controls it, and if the bulb is cold, then switch number 3, the one you did not touch, controls it.
  4. Split the resulting number “123” into 2 parts - 1 and 23. Those numbers will be 2 results. “1” will be result of “first number minus second number”. “23” will be result of “first number plus second number”. So it’s easy to see that those 2 numbers will be 12 and 11. 12 - 11 = 1. 12 + 11 = 23. Write them together and you get 123.. So the answer is 12 + 11 = 123.
  5. You can turn a square manhole cover sideways and drop it down the diagonal of the manhole. You cannot drop a round manhole cover down the manhole. Therefore, round manhole covers are safer.
  6. Failed Parachute.