How do you go from 98 to 720 using just one letter?

Can you make the below equation true by using any three numbers from "1, 3, 5, 7, 9, 11, 13 and 15"?

( ) + ( ) + ( ) = 30

Can you replace the question mark with the correct number in the below table sequence?

What month of the year has 28 days?

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

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?

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

What happened when the wheel was invented?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?