Mathematics Delhi set 1 2012-2013 English Medium Class 10 Question Paper Solution

The common difference of the AP `1/p,  (1-p)/p,  (1-2p)/p,...` is ______.

p

-p

-1

1

In Fig. 1, PA and PB are two tangents drawn from an external point P to a circle with centre C and radius 4 cm. If PA ⊥ PB, then the length of each tangent is:

(A) 3 cm

(B) 4 cm

(C) 5 cm

(D) 6 cm

In Fig.2, a circle with centre O is inscribed in a quadrilateral ABCD such that, it touches the sides BC, AB, AD and CD at points P, Q, R and S respectively, If AB = 29 cm, AD = 23 cm, ∠B = 90° and DS = 5 cm, then the radius of the circle (in cm.) is:

(A) 11

(B) 18

(C) 6

(D) 15

The angle of depression of a car, standing on the ground, from the top of a 75 m high tower, is 30°. The distance of the car from the base of the tower (in m.) is:

(A)`25sqrt3` 

(B)`50sqrt3`

(C)`75sqrt3`

(D) 150

The probability of getting an even number, when a die is thrown once, is :

(A) `1/2`

(B)`1/3`

(C)`1/6`

(D)`5/6`

(A) `1/2`

(B)`1/3`

(C)`1/6`

(D)`5/6`

A box contains 90 discs, numbered from 1 to 90. If one disc is drawn at random from the box, the probability that it bears a prime number less than 23, is ______.

`7/90`

`9/90`

`1/9`

`10/90`

`4/15`

`4/45`

`8/89`

\[\frac{9}{89}\]

In Fig. 3, the area of triangle ABC (in sq. units) is:

(A) 15

(B) 10

(C) 7.5

(D) 2.5

If the difference between the circumference and the radius of a circle is 37 cm, then using`22/7`, the circumference (in cm) of the circle is:

(A) 154

(B) 44

(C) 14

(D) 7

Solve the following quadratic equation for x:

`4sqrt3x^3+5x-2sqrt3=0`

How many three-digit numbers are divisible by 7?

In Fig. 4, a circle inscribed in triangle ABC touches its sides AB, BC and AC at points D, E and F respectively. If AB = 12 cm, BC = 8 cm and AC = 10 cm, then find the lengths of AD, BE and CF.

Prove that a parallelogram circumscribing a circle is a rhombus.

A card is drawn at random from a well shuffled pack of 52 playing cards. Find the probability that the drawn card is neither a king nor a queen ? 

Two circular pieces of equal radii and maximum area, touching each other are cut out from a rectangular card board of dimensions 14 cm × 7 cm. Find the area of the remaining card board. `[\text{Use}pi=22/7]`

For what value of k, are the roots of the quadratic equation kx (x − 2) + 6 = 0 equal ?

Find the number of terms of the AP 18, `15``1/2` 13, ….., `49``1/2` and find the sum of all its terms n?

Construct a triangle of sides 4 cm, 5cm and 6cm and then a triangle similar to it whose sides are `2/3` of the corresponding sides of the first triangle. Give the justification of the construction.

The horizontal distance between two poles is 15 m. The angle of depression of the top of first pole as seen from the top of second pole is 30°. If the height of the second pole is 24 m, find the height of the first pole. Use`[sqrt3=1.732]`

prove  that the points A (7, 10), B(-2, 5) and C(3, -4) are the vertices of an isosceles right triangle.

Find the ratio in which the y-axis divides the line segment joining the points (−4, − 6) and (10, 12). Also find the coordinates of the point of division ?

In Fig.5, AB and CD are two diameters of a circle with centre O, which are perpendicular to each other. OB is the diameter of the smaller circle. If OA = 7 cm, find the area of the shaded region. `[\text{Use}pi=22/7]`

A vessel is in the form of hemispherical bowl surmounted by a hollow cylinder of same diameter. The diameter of the hemispherical bowl is 14 cm and the total height of the vessel is 13 cm. Find the total surface area of the vessel. `[\text{Use}pi=22/7]`

A wooden toy was made by scooping out a hemisphere of same radius from each end of a solid cylinder. If the height of the cylinder is 10 cm, and its base is of radius 3.5 cm, find the volume of wood in the toy. `[\text{Use}pi 22/7]`

In a circle of radius 21 cm, an arc subtends an angle of 60° at the centre. Find the length of the arc.  (Use π = `22/7`)

In a circle of radius 21 cm, an arc subtends an angle of 60° at the centre. Find the area of the sector formed by the arc. (Use π = `22/7`)

`1/(2a+b+2x)=1/(2a)+1/b+1/(2x)`

Sum of the areas of two squares is 400 cm². If the difference of their perimeters is 16 cm, find the sides of the two squares ?

If the sum of first 7 terms of an A.P. is 49 and that of its first 17 terms is 289, find the sum of first n terms of the A.P.

Prove that the tangent at any point of a circle is perpendicular to the radius through the point of contact.

In fig. 6, l and m are two parallel tangents to a circle with centre O, touching the circle at A and B respectively. Another tangent at C intersects the line l at D and m at E. Prove that ∠DOE = 90° ?

The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower from the foot of the building is 60°. If the tower is 50 m high, find the height of the building.

A Group consists of 12 persons, of which 3 are extremely patient, other 6 are extremely honest and rest are extremely kind. A person from the group is selected at random. Assuming that each person is equally likely to be selected, find the probability of selecting a person who is (i) extremely patient (ii) extremely kind or honest.

Which of the above values you prefer more?

The three vertices of a parallelogram ABCD are A(3, −4), B(−1, −3) and C(−6, 2). Find the coordinates of vertex D and find the area of ABCD.

Water is flowing through a cylindrical pipe, of internal diameter 2 cm, into a cylindrical tank of base radius 40 cm, at the rate of 0.4 m/s. Determine the rise in level of water in the tank in half an hour ?

A bucket open at the top is in the form of a frustum of a cone with a capacity of 12308.8 cm³. The radii of the top and bottom circular ends are 20 cm and 12 cm, respectively. Find the height of the bucket and the area of metal sheet used in making the bucket. (use π = 3.14)