# 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 __.

**☛ Check: **NCERT Solutions for Class 10 Maths Chapter 15

**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.

**☛ Related Questions:**

- Which of the following experiments have equally likely outcomes? Explain.(i) A driver attempts to start a car. The car starts or does not start.(ii) A player attempts to shoot a basketball. She/he shoots or misses the shot.(iii) A trial is made to answer a true-false question. The answer is right or wrong.(iv) A baby is born. It is a boy or a girl.
- Why is tossing a coin considered to be a fair way of deciding which team should get the ball at the beginning of a football game?
- Which of the following cannot be the probability of an event?(A) 2 3(B) –1.5(C) 15%(D) 0.7
- If P(E) = 0.05, what is the probability of ‘not E’?

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