In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

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

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Replace the question mark in the picture below.

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

You see me once in June, twice in November, and not at all in May. What am I?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?