If it took eight men ten hours to build a wall, how long would it take four men to build it?

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

What's a single-digit number with no value?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

What has lots of eyes, but can’t see?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?