# Mastering Python Quiz Questions and Answers

### What is the output of print (0.1 + 0.2)?

• none of the above

Explanation :

Neither of 0.1, 0.2 and 0.3 can be represented accurately in binary. The round off errors from 0.1 and 0.2 accumulate and hence there is a difference of 5.5511e-17 between (0.1 + 0.2) and 0.3.

### If a={5,6,7}, what happens when a.add(5) is executed?

• a={5,6,7}

Explanation :

There exists add method for set data type. However 5 isn't added again as set consists of only non-duplicate elements and 5 already exists in the set. Execute in python shell to verify.

### Which of the following best describes inheritance?

• Ability of a class to derive members of another class as a part of its own definition

Explanation :

If the class definition is class B(A): then class B inherits the methods of class A. This is called inheritance.

### What is the result of round(0.5) - round(-0.5)?

• 0

Explanation :

Python rounds off numbers away from 0 when the number to be rounded off is exactly halfway through.