# 10th Maths Paper Solutions Set 2 : CBSE Delhi Previous Year 2009

General Instructions:
1. All questions are compulsory.
2. The question paper consists of 30 questions divided into four sections - A, B, C and D. Section A comprises of ten questions of 1 mark each, Section B comprises of five questions of 2marks each, Section C comprises of ten questions of 3 marks each and Section D comprises of five questions of 6marks each.
3. All questions in Section A are to be answered in one word, one sentence or as per the exact requirement of the question.
There is no overall choice. However, an internal choice has been provided in one question of 2 marks each, three questions of 3 marks each and two questions of 6 marks each. You have to attempt only one of the alternatives in all such questions.
4. In question on construction, the drawing should be neat and as per the given measurements.
5. Use of calculators is not permitted.
Q1 :

In Fig. 1, CP and CQ are tangents to a circle with centre O. ARB is another tangent touching the circle at R. If CP = 11 cm, and BC = 7 cm, then find the length of BR. Fig. 1

It is given that CP and CQ are the tangents from the same point C.

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

CP = CQ = 11 cm [CP = 11 cm]

∴CQ = 11 cm

⇒ CB + BQ = 11 cm

⇒ 7 cm + BQ = 11 cm [BC = 7 cm]

⇒ BQ = 11 cm − 7 cm = 4 cm

According to the given figure, BQ and BR are the tangents from the same point B.

∴BR = BQ = 4 cm.

Thus, the length of BR is 4 cm.

Q2 :

If , then find the value of (2cot2θ + 2).

It is given that .  Q3 :

For what value of p are 2p + 1, 13 and 5p − 3, three consecutives terms of an A.P.?

Let 2p + 1, 13, and 5p − 3 be the three consecutive terms of an A.P.

The difference between any two consecutive terms of an A.P. is equal.

∴2nd term − 1st term = 3rd term − 2nd term

⇒ 13 − (2p + 1) = 5p − 3 − 13

⇒ 13 − 2p − 1 = 5p − 16

⇒ 12 − 2p = 5p − 16

⇒ 28 = 7p Thus, if p = 4, then 9, 13, and 17 are the three consecutive terms of an A.P.

Q4 :

A cylinder and a cone are of same base radius and of same height. Find the ratio of the volume of cylinder to that of the cone.

Q5 :

Write the median class of the following distribution:

Classes Frequency

0−10 4

10−20 4

20−30 8

30−40 10

40−50 12

50−60 8

60−70 4

Q6 :

In Fig, 2, ∠M = ∠N = 46°. Express x in terms of a, b and c where a, b and c are lengths, of LM, MN and NK respectively. Q7 :

For what value of k, (−4) is a zero of the polynomial x2x − (2k + 2)?

Q8 :

Find the distance between the points and .

Q9 :

Find the value of a so that the point (3, a) lies on the line represented by
2x − 3y = 5.

Q10 :

The decimal expansion of the rational number will terminate after how many places of decimals.

Q11 :

Two tangents PA and PB are drawn to a circle with centre O from an external point P. Prove that ∠APB = 2 ∠OAB. Fig. 3

OR

Prove that the parallelogram circumscribing a circle is a rhombus.

Q12 :

If the polynomial is divided by another polynomial , the remainder comes out to be , find a and b.

Q13 :

If Sn, the sum of first n terms of an A.P. is given by Sn = , then find its nth term.

Q14 :

Simplify: Q15 :

Find the value(s) of k for which the pair of linear equations kx + 3y = k − 2 and 12x + ky = k has no solution.

Q16 :

Prove that is an irrational number.

Q17 :

The king, queen and jack of clubs are removed from a deck of 52 playing cards and the remaining cards are shuffled. A card is drawn from the remaining cards. Find the probability of getting a card of (i) heart (ii) queen (iii) clubs.

Q18 :

The sum of 5th and 9th terms of an A.P. is 72 and sum of 7th and 12th terms is 97. Find the A.P.

Q19 :

In Fig. 4, ΔABC is right angled at C and DE ⊥ AB. Prove that ΔABC ∼ ΔADE and hence find the lengths of AE and DE. Fig. 4

OR

In Fig, 5, DEFG is a square and ∠BAC = 90°. Show that DE2 = BD × EC. Fig. 5

Q20 :

If P (x, y) is any point on the line joining the points A (a, 0) and B (0, b), then show that .

Q21 :

Solve the following pair of equations: Q22 :

Find the point on x-axis which is equidistant from the points (2, − 5) and (− 2, 9)

OR

The line segment joining the points P (3, 3) and Q (6, − 6) is trisected at the points A and B such that A is nearer to P. If A also lies on the line given by 2x + y + k = 0, find the value of k.

Q23 :

Find the value of sin 30° geometrically.

OR

Without using trigonometrical tables, evaluate: Q24 :

Construct a ΔABC in which BC = 6.5 cm, AB = 4.5 cm and ∠ABC = 60°. Construct a triangle similar to this triangle whose sides are of the corresponding sides of the triangle ABC.

Q25 :

In Fig. 6, PQ = 24 cm, PR = 7 cm and O is the centre of the circle. Find the area of shaded region (take π = 3.14) Fig. 6

Q26 :

From a solid cylinder whose height is 8 cm and radius 6 cm, a conical cavity of height 8 cm and of base radius 6 cm, is hollowed out. Find the volume of the remaining solid correct to two places of decimals. Also find the total surface area of the remaining solid. (take π = 3.1416)

OR

In Fig. 7, ABC is a right triangle right angled at A. Find the area of shaded region if AB = 6 cm, BC = 10 cm and O is the centre of the incircle of ΔABC.

(take π = 3.14) Q27 :

Prove that, in a right triangle, the square of the hypotenuse is equal to the sum of squares of the other two sides.

Using the above, prove the following:

Prove that, in a ΔABC, if AD is perpendicular to BC, then AB2 + CD2 = AC2 + BD2.

Q28 :

The angles of depression of the top and bottom of an 8 m tall building from the top of a multi-storeyed building are 30° and 45°, respectively. Find the height of the multi-storeyed building and the distance between the two buildings.

Q29 :

The following table gives the daily income of 50 workers of a factory:

 Daily income (in Rs.) 100−120 120−140 140−160 160−180 180−200 Number of workers 12 14 8 6 10

Find the Mean, Mode and Median of the above data.

Q30 :

The sum of the squares of two consecutive odd numbers is 394. Find the numbers.

OR

Places A and B are 100 km apart on a highway. One car starts from A and another from B at the same time. If the cars travel in the same direction at different speeds, they meet in 5 hours. If they travel towards each other, they meet in 1 hour. What are the speeds of the two cars?