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 15
Extra 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 by
P (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
