CBSE Class 10 Question Paper 2025 Solution Data Science

Marking Scheme
Strictly Confidential
(For Internal and Restricted use only)
Secondary School Examination, 2025
SUBJECT NAME DATA SCIENCE (Q.P. CODE 106)

General Instructions: -
1 You are aware that evaluation is the most important process in the actual and correct
assessment of the candidates. A small mistake in evaluation may lead to serious
problems which may affect the future of the candidates, education system and
teaching profession. To avoid mistakes, it is requested that before starting evaluation,
you must read and understand the spot evaluation guidelines carefully.
2 “Evaluation policy is a confidential policy as it is related to the confidentiality of
the examinations conducted, Evaluation done and several other aspects. Its’
leakage to public in any manner could lead to derailment of the examination
system and affect the life and future of millions of candidates. Sharing this
policy/document to anyone, publishing in any magazine and printing in News
Paper/Website etc. may invite action under various rules of the Board and IPC.”
3 Evaluation is to be done as per instructions provided in the Marking Scheme. It should
not be done according to one’s own interpretation or any other consideration. Marking
Scheme should be strictly adhered to and religiously followed. However, while
evaluating, answers which are based on latest information or knowledge and/or
are innovative, they may be assessed for their correctness otherwise and due
marks be awarded to them. In class-XII, while evaluating two competency-based
questions, please try to understand given answer and even if reply is not from
marking scheme but correct competency is enumerated by the candidate, due
marks should be awarded.
4 The Marking Scheme carries only suggested value points for the answers.
These are in the nature of Guidelines only and do not constitute the complete answer.
The students can have their own expression and if the expression is correct, the due
marks should be awarded accordingly.
5 The Head-Examiner must go through the first five answer books evaluated by each
evaluator on the first day, to ensure that evaluation has been carried out as per the
instructions given in the Marking Scheme. If there is any variation, the same should be
zero after deliberation and discussion. The remaining answer books meant for
evaluation shall be given only after ensuring that there is no significant variation in the
marking of individual evaluators.
6 Evaluators will mark( √ ) wherever answer is correct. For wrong answer CROSS ‘X” be
marked. Evaluators will not put right (✓)while evaluating which gives an impression
that answer is correct and no marks are awarded. This is most common mistake
which evaluators are committing.
7 If a question has parts, please award marks on the right-hand side for each part.
Marks awarded for different parts of the question should then be totaled up and written
in the left-hand margin and encircled. This may be followed strictly.
8 If a question does not have any parts, marks must be awarded in the left-hand margin
and encircled. This may also be followed strictly.

106 1 P.T.O.

9 If a student has attempted an extra question, answer of the question deserving more
marks should be retained and the other answer scored out with a note “Extra
Question”.
10 No marks to be deducted for the cumulative effect of an error. It should be penalized
only once.
11 A full scale of marks __________(example 0 to 80/70/60/50/40/30 marks as given in
Question Paper) has to be used. Please do not hesitate to award full marks if the
answer deserves it.
12 Every examiner has to necessarily do evaluation work for full working hours i.e., 8
hours every day and evaluate 20 answer books per day in main subjects and 25
answer books per day in other subjects (Details are given in Spot Guidelines).This is in
view of the reduced syllabus and number of questions in question paper.
13 Ensure that you do not make the following common types of errors committed by the
Examiner in the past:-
● Leaving answer or part thereof unassessed in an answer book.
● Giving more marks for an answer than assigned to it.
● Wrong totaling of marks awarded on an answer.
● Wrong transfer of marks from the inside pages of the answer book to the title
page.
● Wrong question wise totaling on the title page.
● Wrong totaling of marks of the two columns on the title page.
● Wrong grand total.
● Marks in words and figures not tallying/not same.
● Wrong transfer of marks from the answer book to online award list.
● Answers marked as correct, but marks not awarded. (Ensure that the right tick
mark is correctly and clearly indicated. It should merely be a line. Same is with the
X for incorrect answer.)
● Half or a part of answer marked correct and the rest as wrong, but no marks
awarded.
14 While evaluating the answer books if the answer is found to be totally incorrect, it
should be marked as cross (X) and awarded zero (0)Marks.
15 Any unassessed portion, non-carrying over of marks to the title page, or totaling error
detected by the candidate shall damage the prestige of all the personnel engaged in
the evaluation work as also of the Board. Hence, in order to uphold the prestige of all
concerned, it is again reiterated that the instructions be followed meticulously and
judiciously.
16 The Examiners should acquaint themselves with the guidelines given in the
“Guidelines for Spot Evaluation” before starting the actual evaluation.
17 Every Examiner shall also ensure that all the answers are evaluated, marks carried
over to the title page, correctly totaled and written in figures and words.
18 The candidates are entitled to obtain photocopy of the Answer Book on request on
payment of the prescribed processing fee. All Examiners/Additional Head
Examiners/Head Examiners are once again reminded that they must ensure that
evaluation is carried out strictly as per value points for each answer as given in the
Marking Scheme.

106 2

Set 4 >
$
MARKING SCHEME
DATA SCIENCE

SECTION A
(Objective Type Questions) (24 Marks)

1. Answer any 4 out of the given 6 questions on Employability Skills. 41=4

(i) (A) The receiver transmits the message through one medium or
another. 1

(ii) (C) becoming self-aware, self-monitoring and self-correcting 1

(iii) (B) Self-motivation 1

(iv) (A) Viruses 1

(v) (D) Entrepreneurship 1

(vi) (A) Sustainable development 1

2. Answer any 5 out of the given 6 questions. 51=5

(i) (B) Sorted 1

(ii) (A) A method which shows the probable values for a variable and
how often they occur. 1

(iii) (C) Observer Bias 1

(iv) (B) Data merging 1

(v) (A) Privacy 1

(vi) False 1

106 3 P.T.O.

3. Answer any 5 out of the given 6 questions. 51=5

(i) (B) top, left 1

(ii) (D) Four 1

(iii) (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the
correct explanation of Assertion (A). 1

(iv) (B) Z-Score 1

(v) (C) Primary 1

(vi) (B) with Confidentiality 1

4. Answer any 5 out of the given 6 questions. 51=5

(i) The division of a small set of data from a large set of data is known as a
subset 1

(ii) (A) Probabilities 1

(iii) (B) Central Limit Theorem 1

(iv) (A) Positive, Negative 1

(v) (C) Interquartile range 1

(vi) False 1

5. Answer any 5 out of the given 6 questions. 51=5

(i) True 1

(ii) (D) Continuous 1

(iii) (B) Probability 1

(iv) (A) Standard Deviation 1

(v) (B) Percentile 1

(vi) (C) Discard 1

106 4

SECTION B
(Subjective Type Questions) (26 Marks)
Answer any 3 out of the given 5 questions based on Employability Skills in
20 – 30 words each. 32=6

6. Interpersonal Communication: This form of communication takes
place between two individuals and is thus one-to-one conversation, It
can be formal or informal. 2
(1 mark for
Examples correct
definition 1
(i) A manager discussing performance with an employee mark for
(ii) Two friends discussing homework correct
example)
(iii) Two people talking to each other over phone or video call

7. Stress management techniques : 2
( 1 mark for
 Time management 2

 Physical exercise and fresh air each correct
technique)
 Healthy diet
 Positivity
 Organizing academic life and no delaying
 Proper Sleep
(Any four)

8. Antivirus monitors the data coming in and out of a computer and 2
(2 mark for
prevents viruses from entering. Anti-virus can also detect and clean correct
viruses that may have entered a computer. answer)

9. Myth 2
The money used to start a business is called capital. Capital is (1 mark for
mentioning
important for starting a business. However every business does not
myth or fact
need a lot of capital to start. Depending on how much money you have
1 mark for
or can borrow, you can start a business with that much money. Once justification)
you make more money, you can put into your business to make it
bigger.

106 5 P.T.O.

10. Problems related to sustainable development are: 2

 Food : The amount of rich, fertile land needed to grow crops, (1 mark for
each correct
such as wheat, rice, etc. is becoming less as the are also getting
problem
depleted and lots of chemicals are spoiling the soil due to use and its
of chemical fertilizers. explanation)

 Water : We use fresh water from rivers and ponds for drinking
and cleaning but dump garbage into them. The rivers and
ponds are getting polluted. This way, after several years, we
will not have any clean water to drink.

 Fuel : We are using a lot of wood from trees as fuels and for
construction of homes and furniture. As more and more trees
are being cut, it is affecting the climate of the place. Extreme
weather conditions, such as floods, extreme cold or heat, are
seen in many places, which affect the people living there.

(Any two)

Answer any 4 out of the given 6 questions in 20 – 30 words each. 42=8

11. The Standard Deviation is a measure of how spread out the numbers 2
are. To be specific, standard deviation represents how much the (1 mark for correct
definition
data is spread out around the mean or an average. For example, to 1 mark for correct
example)
find out if all points are close to the average or there are lost of
points way above or below the average.

12. Discrete data is the data that takes only specified values. 2
(1 mark for
For example, if you give a test, you can either pass or fail. So, data correct definition
1 mark for
is discrete in this case as it has only two specified outcomes.
correct example)

13. Recall Bias is a type of measurement bias. It is common at the 2
(1 mark for correct
data labelling stage of any project. definition 1 mark for
This type of bias occurs when we label similar type of data correct
reason for
inconsistently, thus resulting in lower accuracy. occurrence)

14. Z-Score is very helpful to standardize the values of a normal 2
distribution by converting them into z-score because : (1 mark
for each
correct
106 6 point)

(i) It gives us an opportunity to calculate the probability of a
value occurring within a normal distribution.
(ii) Z-score allows us to compare two values that are from the
different samples.

15. One-to-many join is a type of joining technique in which one record 2
of a table can be related to one or many records in another table. (1 mark for
For example correct
explanation
One student can have multiple books issued by school library. 1 mark for
correct
16. In situations where you just have a single page or one file to example)
2
discard, cutting the documents can be an appropriate method to (1 mark for
discard the documents. each correct
While cutting the documents, it should be cut into small pieces to point)
ensure no sensitive information is readable.

Answer any 3 out of the given 5 questions in 50 – 80 words each. 34=12

17. In order to find standard deviation :
Step 1 : Calculate the mean by adding up all the data pieces and 4
(1 mark each
dividing it by the number of pieces of the data. for first three
Step 2 : Subtract mean from every value. steps
Step 3 : Square each of the differences. 1
mark
2
Step 4 : Find the average of squared numbers calculated in point
each for last
number 3 to find the variance. two steps)
Step 5 : Lastly, find the square root of variance. That is the standard
deviation.

18. Uniform distribution is one in which likelihood of occurrence of each
4
event is same.
(1 mark for
correct
Probability Table for tossing two coins is as follows : definition
Outcome Probability 3 marks for
Head-Head 0·25 correct
probability
Head-Tail 0·25 table)
Tail Head 0·25
Tail-Tail 0·25
All Else 0

106 7 P.T.O.

19. (a) In Data Science, bias is a deviation from the expected outcome 4
(1 mark
in the data. Fundamentally, bias can also be called as an error
each for
in data. parts a
and b 2
(b) Bias basically occurs because of sampling and estimation. marks for
(c) Predictive models often consider only the data that is used for part c)

training. In fact, they know no other reality other than the data
that is fed in their system. Naturally, if the data that is fed into
the system is biased, model accuracy and fidelity are
compromised. Biased models can also tend to discriminate
against certain groups of people. Therefore, it is very
important to eliminate the bias to avoid these risks.

4
20. Steps to calculate decile :
(1 mark
(a) Find out the number of data or variables in the sample or for each
correct
population. This is denoted by n. step)
(b) In the next step, sort all the data or variables in the sample
population in ascending order.

(c) In the next step, based on the decile that is required, calculate
decile by using the formula :
1 ´ (n + 1 )
Di =
th
10 Data

(d) Lastly, based on the decile value, determine the corresponding
variable from amongst the population data.

21. It is important to understand that digital information is the most 4
vulnerable information that you may possess. With the increased (1 mark for
correct need
amount and intensity of cyber-attacks, it is important for all of us to 3 marks for
corret ways –
make sure that we discard the digital data in a proper way. This helps minimum three
us to prevent unauthorized access to the data. points to be
mentioned)

106 8

Once you are done with the job and you no longer need the user data,
you can go ahead and clean out the data from the memory.

Even while storing the data in your device, you can encrypt the data to
make sure that even in case of data leak, hackers are not able to read
your data. You can also format the computer drive/hard disk where
the client confidential data was stored for a clean discarding. Please
note that in most of the devices, if you do a soft delete of a particular
file, this file deletes from the original space and gets stored in a
temporary folder from wherev one can easily restore these files.
Hence, it is important that confidential data is cleaned out or
formatted from the disk permanently and no one is able to restore the
files that we have deleted.

106 9 P.T.O.