What is in seasons, seconds, centuries and minutes but not in decades, years or days?

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?

What always comes into a house through the keyhole?

Can you count the number of children in the picture below

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

What work can one never finish?

Can you fill the blank with the correct number?

6 30 870 756030 _____