# CBSE Class 9 Mathematics/Probability – Chapter 15/ Model Questions.

**CBSE Class 9 Mathematics /Probability – Chapter 15 is about the Model Questions that you can expect for Yearly Examination. Here you can find out practice problems for Class 9 Mathematics. This worksheet is designed for CBSE Class 9 students.**

**CBSE Class 9 Mathematics/ Probability – Chapter 15Extra Questions for Practice/Model Questions• An event for an experiment is the collection of some outcomes of the experiment.• The chance of happening of any event is expressed as a numerical value which is called Probability.• The probability of an event lies between 0 and 1 (0 and 1 inclusive)• The probability of a sure event is 1• The probability of an impossible event is 0• The empirical (or experimental) probability P(E) of an event E is given byP (E) = Number of trials in which E has happened/Total number of trials.**

**Answer the following:**

**In a cricket match, a batswoman hits a boundary 6 times out of 30 balls she plays. Find the probability that she did not hit a boundary?**

Solution:

Probability that she did not hit a boundary = 24/30 = 4/5**Seven bags of wheat flour each marked 3 kg, actually contained the following weights of flour in kg:**

2.98, 3.05, 3.03, 3.00, 3.06, 2.96, 3.01

Find the probability that any of these bags chosen at random contains more than 3 kg of flour?

Solution:

Probability of the bags that contain more than 3 kg of flour = 4/7**A coin is tossed 100 times with the following frequencies:**

Head: 55, Tail: 45

Compute the probability of each event?

Solution:

P (getting head) = 55/100 = 0.5

P (getting tail) = 45/100 = 0.45**Two coins are tossed simultaneously 100 times and we get**

Two heads: 45 times

One head: 35 times

No head: 20 times

Find the probability of occurrence of each of the events?

Solution:

P (getting two heads) = 45/100 = 0.45

P (getting one head) = 35/100 = 0.35

P (getting no head) = 20/100 = 0.20**If P (event E) = 0.45, then find P (not E)**

Solution:

P (not E) = 1 – P (E) = 1 – 0.45 = 0.55