Probability Class-7 RS Aggarwal ICSE Maths Goyal Brothers Prakashan Chapter-25 Solutions. We provide step by step Solutions of Exercise / lesson-25 Probability for ICSE Class-7 RS Aggarwal Mathematics.
Our Solutions contain all type Questions with Exe-25 to develop skill and confidence. Visit official Website CISCE for detail information about ICSE Board Class-7 Mathematics.
| Board | ICSE |
| Publications | Goyal brothers Prakshan |
| Subject | Maths |
| Class | 7th |
| Chapter-25 | Probability |
| Writer | RS Aggrawal |
| Book Name | Foundation |
| Topics | Solution of Exe-25 to develop skill and confidence |
| Academic Session | 2021-2022 |
Probability Class-7 RS Aggarwal ICSE Maths Goyal Brothers Prakashan Chapter-25 Solutions
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Notes on Probability
Probability means possibility / Chance. It is a branch of mathematics that deals with the occurrence of a random event. The value is expressed from zero to one.
Definition of Probability:
Probability is defined as the numerical method of measuring uncertainty involved in a situation.
It is widely used in the study of mathematics, statistics, gambling, physical science, biological science, weather forecasting, finance etc. to draw conclusions.
Experiment:
An experiment is defined as an action or process that results in well defined outcomes
Formula for Probability
The probability formula is defined as the possibility of an event to happen is equal to the ratio of the number of favourable outcomes and the total number of outcomes.
Formula for Probability
Probability of event to happen P(E) = Number of favourable outcomes/Total Number of outcomes
Random experiment:
An experiment, in which we know all the results, but cannot predict them, is called a random experiment.
Outcomes:
The possible results of an experiment are called the outcomes
Probability of an Event
A combination of outcomes is called an event
Assume an event E can occur in r ways out of a sum of n probable or possible equally likely ways. Then the probability of happening of the event or its success is expressed as
P(E) = r/n
The probability that the event will not occur or known as its failure is expressed as:
P(E’) = (n-r)/n = 1-(r/n)
E’ represents that the event will not occur.
Therefore, now we can say;
P(E) + P(E’) = 1
This means that the total of all the probabilities in any random test or experiment is equal to 1
Probability of an event =
Exe-25
–: End of Probability Class-7 RS Aggarwal Solutions :–
Page 292
Question 1:
When a coin was tossed 200 times, we obtained
Head : 118 times and Tail : 82 times
When the coin is tossed at random, what is the probability of getting
(i) a head ?
(ii) a tail ?
Answer :
Total number of trials = 200
Number or head obtained = 118
Number of tail obtained = 82
(i) P (getting a head) = Number of head in these trials/Total number of trials
= 118/200
= 59/100
(ii) P (getting a tail) = Number of tails in these trials/Total number of trials
= 82/200
= 41/100
Question 2:
A die is rolled I50 times and the outcomes are noted which are tabulated as shown below:
| Outcome | 1 | 2 | 3 | 4 | 5 | 6 |
| Frequency | 29 | 17 | 24 | 19 | 33 | 28 |
When a die is rolled at random, find the probability of getting a:
(i) 1
(ii) 4
(iii) 5
Answer :
Total number of trials = 150
(i) P (getting 1) = 29/150
(ii) P (getting 4) = 19/150
(iii) P (getting 5) = 33/150
= 11/50
Question 3:
Five cards numbered 1 to 5 are placed in a bag. A card is drawn from the bag 30 times. Each time, the number on the drawn card is noted and the card drawn is replaced. The outcomes are tabulated as shown below :
| Outcome | 1 | 2 | 3 | 4 | 5 |
| Frequency | 4 | 10 | 7 | 5 | 4 |
if a card s now drawn at random, find the probability that the card drawn bears the number :
(i) 2
(ii) 3
(iii) 5
Answer :
Total numbers of trials = 30
(i) P (getting 2) = 10/30
= 1/3
(ii) P (getting 3) = 7/30
(iii) P (getting 5) = 4/30
= 2/15
Question 4:
Two coins are tossed simultaneously 100 times. We obtained :
Two Heads : 23 times; One Head : 56 times; Zero Head : 21 times.
when two coins are tossed at random, what is the probability of getting :
(i) Two Heads ?
(ii) One Head?
(iii) Zero Head ?
Answer :
Total number of trials = 100 times
Number of two heads obtained = 23
Number of one head obtained = 56
Number of zero head = 21
(i) P (getting two heads) = 23/100
(ii) P (getting number of one head) = 56/100
= 28/50
= 14/25
(iii) P (getting zero head) = 21/100
Question 5:
In a survey of 200 employees of a company, it was found that 89 liked the lunch packs provided by the Company while the rest did not. Out of these employees, if one employee is chosen at random, what is the probability that the chosen employee:
(i) likes the lunch pack?
(ii) dislikes the lunch pack?
Answer :
Total number of employees surveyed = 200
Number of employees who like lunch packs = 89
Number of employees who dislikes lunch packs = 200 – 89 = 111
(i) P (chosen employee likes the lunch packs) = 89/200
(ii) P (chosen employee dislikes the lunch packs) = 111/200
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Thanks
Thanks to R.S. Aggarwal because they given all the solutions thank you so much ☺️
A very good source for all the answers I couldn’t get by solving myself. I recommend referring to this but not completdepend8ng on it. Furthermore this is a pretty reliable website for all dumb mathematician like me.
thanks for positive response
kon hai tu me himanshu/pathaan