What number when divided in half becomes zero?

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?

Can you write down eight eights so that they add up to one thousand?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

There is a hypothetical state between the USA and Mexico border 'Tango'.
Here 70 percent of the population have defective eyesight, 75 percent are hard of hearing, 80 percent have Nose trouble and 85 percent suffer from allergies, what percentage (at a minimum) suffer from all four ailments?

The Puzzle: A girl, a boy, and a dog start walking down a road.

They start at the same time, from the same point, in the same direction.

The boy walks at 5 km/h, the girl at 6 km/h.

The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn.
How far does the dog travel in 1 hour?

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?