[CLASS 9] Mathematics MCQs on Probability & Experimental Approach

Mathematics Multiple Choice Questions on “Probability & Experimental Approach”.

1. Two coins were tossed 200 times and the following results were obtained.

Two heads: 55
One head and one tail: 105
Two tails: 40

What is the probability of event of obtaining minimum one head?
a) 0.5
b) 0.8
c) 0.55
d) 0.16

Answer: b
Clarification: Number of events of obtaining minimum one head = 55 + 105
= 160
Hence, P (E) = probability of event of obtaining minimum on head
= (frac{Number ,of ,events ,of ,obtaining ,minimum ,one ,head}{Number ,of ,total ,trials})
= (frac{160}{200})
= 0.8.

2. A dice was thrown 500 times. Frequencies for the outcomes 1, 2, 3, 4, 5, and 6 are given in the table.

What is the probability of getting ‘4’ as outcome?
a) 0.16
b) 0.158
c) 0.156
d) 0.131

Answer: d
Clarification: We can see from the table that we get ‘4’ 79 times out of 500 trials.
Therefore, probability of getting ‘4’ as outcome = (frac{Event ,of ,occurence ,of ,getting ,’4′}{Total ,number ,of ,trials})
= (frac{79}{500})
= 0.158.

3. Marks obtained by a student in a test is shown in the table below.

What is the probability that the student has scored more than 80?
a) 0.6
b) 0.8
c) 0.4
d) 0.5

Answer: a
Clarification: It can be seen that the student have scored 3 out of 5 times more than 80 marks.
Therefore, probability that the student has scored more than 80 = (frac{number ,of ,occurrence ,of ,event}{Total ,number ,of ,trials})
= (frac{3}{5})
= 0.6.

4. 1000 families with 2 children were studied and the following data was collected.

What is the probability that the family has at least one boy?
a) 0.415
b) 0.270
c) 0.73
d) 0.315

Answer: c
Clarification: In this case, having at least one boy means one boy or two boys.
Hence, number of families having at least one boy = 415 + 315 = 730
Therefore, the probability that the family has at least one boy = (frac{number ,of ,families ,having ,at ,least ,one ,boy }{Total ,number ,of ,families} = frac{730}{1000})
= 0.73.

5. 1500 drivers were selected for a study to find a relationship between age and accidents. The data is shown in the table below.

What is the probability of being 18-35 years of age and having more than 1 accidents?
a) 0.06
b) 0.6
c) 0.08
d) 0.1

Answer: a
Clarification: We can see that total number of events of being 18-35 years of age and having more than 1 accidents = 90
Total number of events = 1500
Hence, probability of being 18-35 years of age and having more than 1 accidents = (frac{90}{1500})
= 0.06.

6. 1500 drivers were selected for a study to find a relationship between age and accidents. The data is shown in the table below.

What is the probability of being elder than 35 years of age and having at least one accident?
a) 0.41
b) 0.25
c) 0.354
d) 0.333

Answer: c
Clarification: We can see that total number of events of being elder than 35 years of age and having at least 1 accident = 277 + 78 + 118 + 59
= 532
Total number of events = 1500
Hence, probability of being 18-29 years of age and having more than 1 accidents = (frac{532}{1500})
= 0.354.

7. 1500 drivers were selected for a study to find a relationship between age and accidents. The data is shown in the table below.

What is the probability of being 35-50 years of age and having more no accidents?
a) 0.29
b) 0.35
c) 0.09
d) 0.08

Answer: a
Clarification: We can see that total number of events of being 35-50 years of age and having more than 1 accidents = 145
Total number of events = 1500
Hence, probability of being 18-29 years of age and having more than 1 accidents = (frac{145}{1500})
= 0.29.