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?

Count the number of lines in the image below ?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

What does this rebus means ?

PROG WORKRESS

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

What Deficiency does the below rebus represent?

VIT_MIN

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

My location can be determined by the below rebus.
So where am i ?

Can you place six X (crosses) in below board without making three in a row in any way ?