# Complete the following statements:

(i) Probability of an event E + Probability of the event ‘not E’ = ____.

(ii) The probability of an event that cannot happen is ____. Such an event is called ____.

(iii) The probability of an event that is certain to happen is ____. Such an event is called ____.

(iv) The sum of the probabilities of all the elementary events of an experiment is ____.

(v) The probability of an event is greater than or equal to ____ and less than or equal to ____.

**Solution:**

We use the basic concepts of probability to answer the questions given.

(i) Probability of an event E + Probability of the event ‘not E’ = __ 1 .__

(ii) The probability of an event that cannot happen is __ 0 __. Such an event is called an __impossible event.__

(iii) The probability of an event that is certain to happen is __ 1 __. Such an event is called __sure event__.

(iv) The sum of the probabilities of all the elementary events of an experiment is __ 1 __.

(v) The probability of an event is greater than or equal to __ 0 __ and less than or equal to __ 1 __.

**Video Solution:**

## Complete the following statements: (i) Probability of an event E + Probability of the event ‘not E’ = ____. (ii) The probability of an event that cannot happen is ____. Such an event is called ____. (iii) The probability of an event that is certain to happen is ____. Such an event is called ____. (iv) The sum of the probabilities of all the elementary events of an experiment is ____. (v) The probability of an event is greater than or equal to ____ and less than or equal to ____.

### NCERT Solutions for Class 10 Maths - Chapter 15 Exercise 15.1 Question 1:

**Summary:**

(i) Probability of an event E + Probability of the event ‘not E’ = 1. (ii) The probability of an event that cannot happen is 0. Such an event is called an impossible event. (iii) The probability of an event that is certain to happen is 1. Such an event is called sure event. (iv) The sum of the probabilities of all the elementary events of an experiment is 1. (v) The probability of an event is greater than or equal to 0 and less than or equal to 1.