# Best hard riddles

## Round Manhole Covers

Why are manhole covers round? Do manhole covers really need to be circular?
Manhole covers are round so that they won't fall through the hole into the sewer below them. No matter how you turn the cover, you won't be able to push the cover through the hole. However, if you were to have square manhole covers, you would be able to rotate the cover such that one of the edges of the square cover is lined up with the diagonal line of the square hole, which would allow the cover to fall through, causing countless problems that the general public would rather avoid.
73.93 %

## Two convicts and the escape plan

Two convicts are locked in a cell. There is an unbarred window high up in the cell. No matter if they stand on the bed or one on top of the other they can't reach the window to escape. They then decide to tunnel out. However, they give up with the tunnelling because it will take too long. Finally one of the convicts figures out how to escape from the cell. What is his plan?
His plan is to dig the tunnel and pile up the dirt to climb up to the window to escape.
73.90 %

## 100

Can you arrange four 9's and use of at most 2 math symbols, make the total be 100?
99 / .99 or 99 + 9/9
73.89 %

## First in Earth, second in Heaven

I am first in Earth, second in Heaven, I appear two times in a week. You can only see me once in a year, although I'm in the middle of sea. Who am I?
Answer is E The asnwer is E. As In spelling of Earth E comes first, in Heaven it comes second, in week it comes twice, in a year it comes once and finally in spelling of sea E stands in middle of the spelling.
73.86 %

## I do not eat food.

I do not eat food. But I do enjoy a light meal every day. What am I?
A plant (photosynthesis).
73.81 %
clean

## Silent

In which place are you silent?
In the building ("u" is silent in pronouncing "building".
73.80 %

## What do squirrels give each other

What do squirrels give each other for Valentine’s Day?
Forget-me-nuts.
73.80 %
funny

## Chewing gum to the shoe

What did the chewing gum say to the shoe?
I'm stuck on you.
73.75 %
funny

## City with no people

What city has no people?
Electricity.
73.75 %