Logic Riddles

Logic riddles with answers involve looking at situations and making judgements about them by ruling out impossibilities. If you like solving maths puzzles, you will most probably like logic riddles as well.

Two Angels

You are standing in front of two gates (a left one and a right one) – one leads to Heaven and the other leads to Hell. You don’t know which gate leads where. Beside the gates, there are two angels. One of them always tells the truth and the other always lies, but you don’t know which one is which.

You have one question to ask one of the angels, in order to find out which gate will lead you to Heaven. What would that question be?

Answer

The question is: “What would the other angel say, if I asked which gate leads to Heaven?”. And do exactly the opposite of what the angel says.

If the left gate leads to Heaven:

  • The angel that tells the truth will say that it’s the right gate since it knows that the other angel will lie.
  • The angel that lies will also say that it’s the right gate since it knows that the other angel will tell the truth.

The same explanation applies if the right gate leads to Heaven.

Gold for 7 Days of Work

A contractor is doing work for 7 days at your home. You have a gold bar that is worth $7000. You need to pay him $1000 every day and $7000 in total. You have to pay him in gold by using the gold bar. How can you pay him $1000 worth of gold everyday by cutting the gold bar only twice?

Answer

By cutting the gold bar twice, you can have 3 pieces of gold.

Let the gold bar pieces be GB1, GB2 and GB3. They are worth $1000, $2000 and $4000 respectively.

Day1: Give GB1

Day2: Take GB1, Give GB2

Day3: Give GB1

Day4: Take GB1, GB2 and give GB3

Day5: Give GB1

Day6: Take GB1, Give GB2

Day7: Give GB1

15 Minutes with Burning Ropes

You have two ropes. Each rope can burn in exactly one hour. The ropes are not of the same length or width. Both ropes are also not of uniform width or thickness. The ropes are thick at certain places and thin at other places. Thus, a rope that is half burnt will not necessarily have taken 30 minutes to burn.

By burning the ropes, how do you measure exactly 15 minutes worth of time?

Riddle Answer