Basic Study Material in Mathematics

CLASS X

© Private circulation only

____________________________________________

Don Bosco School

Alaknanda, New Delhi-110019

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

CBSE 2018 / MATHEMATICS CLASS X MAXIMUM MARKS: 80

SECTION – A

Question numbers 1 to 6 carry 1 mark each.

1. If x = 3 is one root of the quadratic equation x 2 – 2kx – 6 = 0, then find the value of k.

2. What is the HCF of smallest prime number and the smallest composite number?

3. Find the distance of a point P(x, y) from the origin.

4. In an AP, if the common difference (d) = –4, and the seventh term (a7 ) is 4, then find the

first term.

5. What is the value of (cos2 67° – sin

2 23°) ?

6. Given ABC ~ PQR, if 𝐴𝐵

𝑃𝑄 =

1

3, then find

ar 𝐴𝐵𝐶

ar PQR

SECTION – B

Question numbers 7 to 12 carry 2 marks each.

7. Given that 2 is irrational, prove that (5 + 3 2) is an irrational number.

8. In the figure, ABCD is a rectangle. Find the values of x and y

9. Find the sum of first 8 multiples of 3.

10. Find the ratio in which P(4, m) divides the line segment joining the points A(2, 3) and

B(6, –3). Hence find m.

11. Two different dice are tossed together. Find the probability : (i) of getting a doublet

(ii) of getting a sum 10, of the numbers on the two dice

12. An integer is chosen at random between 1 and 100. Find the probability that it is :

(i) divisible by 8. (ii) not divisible by 8.

SECTION – C

Question numbers 13 to 22 carry 3 marks each.

13. Find HCF and LCM of 404 and 96 and verify that LCM HCF = Product of the two

given numbers.

14. Find all zeroes of the polynomial (2x 4 – 9x

3 + 5x

2 + 3x – 1) if two of its zeroes are

(2 + 3 ) and (2 – 3).

15. If A(–2, 1), B(a, 0), C(4, b) and D(1, 2) are the vertices of a parallelogram ABCD, find

the values of a and b. Hence find the lengths of its sides.

41

OR

If A(–5, 7), B(–4, –5), C(–1, –6) and D(4, 5) are the vertices of a quadrilateral, find the

area of the quadrilateral ABCD.

16. A plane left 30 minutes late than its scheduled time and in order to reach the destination

1500 km away in time, it had to increase its speed by 100 km/h from the usual speed.

Find its usual speed.

17. Prove that the area of an equilateral triangle described on one side of the square is equal

to half the area of the equilateral triangle described on one of its diagonal.

OR

If the area of two similar triangles are equal, prove that they are congruent.

18. Prove that the lengths of tangents drawn from an external point to a circle are equal.

19. If 4 tan =3, evaluate 4 sin – cos +1

4 sin + cos −1

OR

If tan 2A = cot (A – 18°), where 2A is an acute angle, find the value of A.

20. Find the area of the shaded region in Figure, where arcs drawn

with centres A, B, C and D intersect in pairs at mid-points P, Q, R

and S of the sides AB, BC, CD and DA respectively of a square

ABCD of side 12 cm. [Use =3.14]

21. A wooden article was made by scooping out a hemisphere from each end of a solid

cylinder, as shown in Fig. If the height of the cylinder is 10 cm and

its base is of radius 3.5 cm. Find the total surface area of the article.

OR

A heap of rice is in the form of a cone of base diameter 24 m and

height 3.5 m. Find the volume of the rice. How much canvas cloth is

required to just cover the heap ?

22. The table below shows the salaries of 280 persons :

Calculate the median salary of the data.

SECTION – D Question numbers 23 to 30 carry 4 marks each.

23. A motor boat whose speed is 18 km/hr in still water takes 1hr more to go 24 km upstream

than to return downstream to the same spot. Find the speed of the stream.

42

OR

A train travels at a certain average speed for a distance of 63 km and then travels at a

distance of 72 km at an average speed of 6 km/hr more than its original speed. If it takes

3 hours to complete total journey, what is the original average speed ?

24. The sum of four consecutive numbers in an AP is 32 and the ratio of the product of the

first and the last term to the product of two middle terms is 7 : 15. Find the numbers.

25. In an equilateral triangle ABC, D is a point on side BC such that BD = 1

3 BC.

Prove that 9 AD2 = 7 AB

2

OR

Prove that, in a right triangle, the square on the hypotenuse is equal to the sum of the

squares on the other two sides.

26. Draw a triangle ABC with BC = 6 cm, AB = 5 cm and ABC = 60°. Then construct a

triangle whose sides are 3

4 of the corresponding sides of the ABC.

27. Prove that : sin A – 2 si n3 A

2 co s3 A – cos A = tan A.

28. The diameters of the lower and upper ends of a bucket in the form of a frustum of a cone

are 10 cm and 30 cm respectively. If its height is 24 cm, find :

(i) The area of the metal sheet used to make the bucket

(ii) (ii) Why we should avoid the bucket made by ordinary plastic ? [Use = 3.14 ]

29. As observed from the top of a 100 m high light house from the sea-level, the angles of

depression of two ships are 30 and 45. If one ship is exactly behind the other on the

same side of the light house, find the distance between the two ships. [Use 3 = 1.732]

30. T

******

43

CBSE(DELHI) – 2019 / MATHEMATICS CLASS X MARKS: 80

SECTION – A

Question numbers 1 to 6 carry 1 mark each.

1. Two positive integers a and b can be written as a = x3y

2 and b = xy

3. x, y are prime numbers.

Find LCM (a, b).

2. How many two digits numbers are divisible by 3?

3. In Fig. 1, DE||BC, AD = 1 cm and BD = 2 cm.

What is the ratio of the ar(Δ ABC) to the ar(ΔADE)?

4. Find the coordinates of a point A, where AB is the diameter of a circle whose centre is (2, –3)

and B is the point (1, 4).

5. For what values of k, the roots of the equation x2 + 4x + k = 0 are real?

OR

Find the value of k for which the roots of the equation 3x2 – 10x + k = 0 are reciprocal of each

other.

6. Find A if tan 2A = cot (A – 24o)

OR

Find the value of (sin2 33

o + sin

2 57

o)

SECTION – B

Question numbers 7 to 12 carry 2 marks each.

7. Find, how many two digits numbers are divisible by 7

OR

If the sum of first n terms of an AP is n2, then find its 10

th term

8. A game consists of tossing a coin 3 times and noting the outcome each time. If getting the

same results in all tosses is a success, find the probability of losing the game.

9. Find the ratio in which the segment joining the points (1,-3) and (4, 5) is divided by the x-

axis ?. Also find the coordinates of this point on x –axis

10. A die is thrown twice. Find the probability of getting a number which (i) is a prime number

(ii) lies between 2 and 6

44

11. Find the value of c if the system of equations cx+ 3y + (3 - c) = 0 , 12x +cy - c = 0 has

infinitely many solutions

12. Find the HCF of 1260 and 7344 using Euclid’s algorithm

OR

Prove that every positive odd integer is of the form (4q+1) or (4q+3), where q is some integer

13. Find all zeroes of the polynomial if 3x3 +10x

2 -9x-4 if one of its zero is 1

14. PQ is a chord of length 8 cm of a circle of radius 5 cm. The

tangents at P and Q intersect at a point T (see figure). Find the

length TP.

15. Prove that 2+ 3

5 is an irrartonal number, given that 3 is an

irrational number

16.

OR

Prove that (1+ cot A –cosec A ) ( 1+ tan A +sec A ) = 2

17. A father's age is 3 times the sum of ages of his two children. After 5 years his age will be

twice the sum of ages of two children. Find the present age of father.

OR

A fraction becomes 1/3 when 2 is subtracted from the numerator and it becomes ½ when 1 is

subtracted from the denominator. Find the fraction

18. Find the point on y axis which is equidistant from the points (5, -2 ) and ( -3, 2)

OR

The line segment joining the points A(2,1) and B(5, -8) is trisected at the points P and Q such

that P is nearer to A. If P also lies on the line given by 2x – y + k = 0, find the value of k

19. Find the mode of the following frequency distribution

Class 0-10 10-20 20-30 30-40 40-50 50-60 60-70

Frequency 8 10 10 16 12 6 7

20. Water in a canal, 6m wide and 1.5m deep, is flowing with a speed of 10 km/hour. How

much area will it irrigate in 30 minutes; if 8cm standing water is needed?

45

21. In the figure, <ACB = 90o and CD AB , prove that CD

2 = BD X AD .

OR

If P and Q are the points on side CA and CB of triangle ABC, right angled at C, prove that

(AQ2 +BP

2 ) = (AB

2 + PQ2)

22. Find the area of the shaded region in the figure, if ABCD is a

rectangle with sides 8cm and 6cm and O is the centre of the circle

(Take π = 3.14)

SECTION – D Question numbers 23 to 30 carry 4 marks each.

23. If sec θ = x + 1

4𝑥 , x≠ 0, find (sec θ + tan θ ).

24. Prove that the ratio of the areas of two similar triangles is equal to the square of the ratio of

their corresponding sides.

25. The following distribution gives the daily income of 50 workers of a factory

Daily income (in Rs) 200-220 220-240 240-260 260-280 280-300

Number of workers 12 14 8 6 10

Convert the distribution above to a ‘less than type’ cumulative frequency distribution and draw

its ogive.

OR

The table below shows the daily expenditure on food of 25 households in a locality. Find the

mean daily expenditure on food

Daily

expenditure 100-150 150-200 200-250 250-300 300-350

Number of

households 4 5 12 2 2

46

26. Construct a triangle ABC in which CA= 6cm, AB = 5cm and <BAC = 45o. Then construct a

triangle whose sides are 3/5 of the corresponding sides of ABC

27. A bucket is in the form of a frustum of a cone with a capacity of 12308.8 cm3

of water. The

radii of the top and bottom circular ends are 20 cm and 12 cm respectively. Find the height of the

bucket and also the area of the metal sheet used in its making (Take π = 3.14)

28. A man in a boat rowing away from a light-house 100m high takes 2min to change the angle

of elevation of the top of the lighthouse from 60o to 45

o. Find the speed of the boat.

[use 𝟑 = 1.732 ]

OR

Two poles of equal heights are standing opposite each other on either side of the roads, which is

80 m wide. From a point between them on the road, the angles of elevation of the top of the poles

are 60o and 30

o respectively. Find the height of the poles and the distances of the point from the

poles.

29. Two water taps together can fill a tank in 15/8 hrs. The tap with longer diameter takes 2

hours less than the tap with smaller one to fill the tank separately. Find the time in which each

tap can fill the tank separately

OR

A boat goes 30 km upstream and 44 km downstream in 10 hours .In 13 hours, it can go 40 km

upstream and 55 km down-stream. Determine the speed of the stream and that of the boat in still

water.

30. If the sum of first 4 terms of an AP is 40 and that of first 14 terms is 280, find the sum of its

first n terms.

*************

47

Cubes of numbers from 1 to 10

No. 1 2 3 4 5 6 7 8 9 10

Cube 1 8 27 64 125 216 343 512 729 1000

48