Test - 2
Test - 2
Mathematics
General Instructions:
The time given at the head of this Paper is the time allowed for writing the answers.
Attempt all questions from Section A and any four questions from Section B.
All work, including rough work, must be clearly shown and must be done on the same sheet as the rest of the
answers.
Omission of essential work will result in a loss of marks.
The intended marks for questions or parts of questions are given in brackets [ ]
Section A
1. Question 1 Choose the correct answers to the questions from the given options: [15]
(a) A retailer purchases a fan for ₹1500 from a wholesaler and sells it to a consumer at 10% profit. If the [1]
sales are intra-state and the rate of GST is 12%, the cost of the fan to the consumer inclusive of tax is:
a) ₹1848 b) ₹1830
c) ₹1650 d) ₹1800
(b) A factory kept increasing its output by the same percentage every year. Then, the percentage, if it is [1]
known that the output is doubled in the last two years, will be
a) 44.4% b) 14.4%
c) 41.4% d) 44.1%
(c) When ax3 + 6x2 + 4x + 5 is divided by (x + 3), the remainder is -7. [1]
The value of constant a is
a) 2 b) -2
c) -3 d) 3
(d) If , then the value of matrix A5 is [1]
a) b)
c) d)
(e) An AP starts with a positive fraction and every alternate term is an integer. If the sum of the first 11 [1]
terms is 33, then the fourth term is
a) 3 b) 6
c) 5 d) 2
(f) If (4, 3) and (-4, -3) are opposite two vertices of a rectangle, then other two vertices are [1]
a) b) a3
c) d) 5 a3
(i) Graph the range of the inequation on the number line. If the solution [1]
set is consider as a diagonal of a square on the number line, then the area of obtained figure, is
a) 11 sq units b) 14 sq units
c) 17 sq units d) 18 sq units
(j) The probability that the minute hand lies from 5 to 15 min in the wall clock, is [1]
a) b)
c) d)
(k) If , then An (where, n is a natural number) is equal to [1]
a) b)
c) d) l2 2
(l) The sum of the squares of the distances of a moving point (x, y) from two fixed points (a, 0) and (- a, [1]
0) is equal to a constant quantity 2b2. The value of x2 + y2 + a2 is equal to
a) b2 b) -a2
c) ab d) -b2
(m) If P, Q, S and R are points on the circumference of a circle of radius r, such that PQR is an equilateral [1]
triangle and PS is a diameter of the circle. Then, the perimeter of the quadrilateral PQSR will be
a) 2( + 1)r b)
c) 2r d)
(n) Observe the data given in three sets [1]
P: 3, 5, 9, 12, x, 7, 2
Q: 8, 2, 1, 5, 7, 9, 3
R: 5, 9, 8, 3, 2, 7, 1
If the ratio between P's and Q's means is 7 : 5, then the ratio between P’s and R’s means is
a) 7 : 5 b) 5 : 7
c) 6 : 7 d) 7 : 6
(o) Assertion (A): Sum of first 10 terms of the arithmetic progression -0.5, -1.0, -1.5, ... is 27.5 [1]
Reason (R): Sum of n terms of an A.P. is given as Sn = where a = first term, d =
common difference.
a) Both A and R are true and R is the b) Both A and R are true but R is not the
correct explanation of A. correct explanation of A.
Find the:
i. Volume of the solid
ii. Curved surface area of the solid
Give your answer correct to the nearest whole number.
(b) The equation of a line is y = 3x - 5. Write down the slope of this line and the intercept made by its on [4]
the Y-axis. Hence or otherwise, write down the equation of a line, which is parallel to the line and
which passes through the point (0, 5).
(c) Use graph paper for this question (Take 2 cm = 1 unit along both x and y axis). ABCD is a [5]
quadrilateral whose vertices are A(2, 2), B(2, - 2), C (0, -1) and D (0, 1)
i. Reflect quadrilateral ABCD on the y-axis and name it as A'B'CD.
ii. Write down the coordinates of A' and B'
iii. Name two points which are invariant under the above reflection.
iv. Name the polygon A'B'CD.
Section B
Attempt any 4 questions
4. Question 4 [10]
(a) The price of a Barbie Doll is ₹ 3136 inclusive tax (under GST) at the rate of 12% on its listed price. A [3]
buyer asks for a discount on the listed price, so that after charging GST, the selling price becomes
equal to the listed price. Find the amount of discount which the seller has to allow for the deal.
(b) Find the values of k, for which the equation x2 + 5kx + 16 = 0 has no real roots. [3]
(c) The mean of the following distribution is 49. Find the missing frequency a. [4]
Frequency 15 20 30 a 10
5. Question 5 [10]
(a) Find the values of x, y, a and b, when . [3]
(b) Two chords AB and CD of a circle intersect each other at a point E inside the circle. If AB = 9 cm, [3]
AE = 4 cm and ED = 6 cm, then find CE.
(c) Determine, whether the polynomial g(x) = x - 7 is a factor of f(x) = x3 - 6x2 - 19x + 84 or not. [4]
6. Question 6 [10]
(a) Find the points of trisection of the line segment joining the points (5, -6) and (-7, 5). [3]
(b) Prove the following identities. [3]
0 - 10 5
10 - 20 9
20 - 30 16
30 - 40 22
40 - 50 26
50 - 60 18
60 - 70 11
70 - 80 6
80 - 90 4
90 - 100 3
find:
i.
ii.
iii.
9. Question 9 [10]
(a) Given: A = {x : 3 < 2x - 1 < 9, x R}, B = {x : 11 3x + 2 23, x R} where R is the set of real [3]
number.
i. Represents A and B on number lines
ii. On the number line also mark A B.
(b) Find the missing frequency for the given frequency distribution table, if the mean, of the distribution [3]
is 18.
Frequency 3 6 9 13 f 5 4
(c) In the given figure, M= N = 46o. Express x in terms of a, b and c, where a, b and c are the lengths [4]
of LM, MN and NK, respectively.
10. Question 10 [10]
(a) The ages of A and B are in the ratio 7 : 8. Six years ago, their ages were in the ratio 5 : 6. Find their [3]
present ages.
(b) Draw a circle of radius 6 cm. From a point 10 cm away from its centre, construct the pair of tangents [3]
to the circle and measure their lengths.
(c) The angle of elevation from a point P of the top of a tower QR, 50 m high is 60o and that the tower [4]
PT from a point Q is 30o. Find the height to the tower PT, correct to the nearest metre.
Solution
Section A
1. Question 1 Choose the correct answers to the questions from the given options:
(i) (a) ₹1848
Explanation: {
Here, selling price of fan = ₹1650
GST on fan = 12% of ₹ 1650
= 1650
= 198
Thus, cost of a fan to the consumer inclusive of tax
= ₹(1650 + 198) = ₹1848
(ii) (c) 41.4%
Explanation: {
Let P be the initial production (2 yr ago) and the increase in production every year be x%. Then, production at the end
of first year = P + =
Production at the end of second year
=P= +
=P =P
Since, the production is doubled in last two years.
P = 2P =2
By quadratic formula, x =
x=
= -100 100 = 100(-1 4 )
= 100 (-1 + 1.414) [ percentage cannot be negative]
= 100(0.414) = 41.4
Hence, the required percentage is 41.4%.
(iii) (a) 2
Explanation: {
Let f(x) = ax3 + 6x2 + 4x + 5
By remainder theorem, f(-3) = -7
a(-3)3 + 6(-3)2 + 4(-3) + 5 = -7
-27a + 54 - 12 + 5 = -7
-27a = -54
a=2
(iv)
(c)
Explanation: {
Given,
Now, A2 = A A =
A4 = A2 A2 =
Now, A5 = A4 A =
(v) (d) 2
Explanation: {
Given, S11 = 33
(2a + 10d) = 33 [ Sn = [2a + (n - 1)d]
a + 5d = 3
i.e. a6 = 3 a4 = 2 [ alternate terms are integers and the given sum is possible]
Other two vertices of the rectangle are (4, -3) and (-4, 3).
(vii) (b) 2BL and 4 ar ( CBL)
Explanation: {
In BMC and EMD, we have
[ if two triangles are similar, then their corresponding sides are proportional]
On taking first two terms, we get
=4
ar ( AEL) = 4 ar ( CBL)
(viii) (b) a3
Explanation: {
Let radius of sphere be a, i.e. OK = OA = a.
Then, the centre O of a sphere will be centroid of the BCD
OA = AB AB = 3(OA)
In right angled OKB,
sin 30o = =
=
OB = 2a
Now, AB = OA + OB = a + 2a = 3a
Now, in right angled BAC,
= tan 30o =
AC = =
AC = units
Now, volume of a cone BCD = (AC)2 AB
= =
Volume of water remaining in the cone = Volume of the cone BCD - Volume of a sphere
= 3 a3 - a3 = a3 cu units
(ix) (d) 18 sq units
Explanation: {
Given,
Explanation: {
We have, = 3l
(xii) (a) b2
Explanation: {
Let P (x, y) be the moving point.
Let given two fixed points be A (a, 0) and B (-a, 0).
According to the given condition,
PA2 + PB2 = 2b2
(x - a)2 + (y - 0)2 + (x + a)2 + (y - 0)2 = 2b2 [by distance formula]
x2 - 2ax + a2 + y2 + x2 + 2ax + a2 + y2 = 2b2
2x2 + 2y2 + 2a2 = 2b2
x2 + y2 + a2 = b2 [dividing both sides by 2]
(xiii) (a) 2( + 1)r
Explanation: {
As PQR is an equilateral triangle, hence PS will be perpendicular to QP and will divide it into 2 equal parts.
Since, P and S will be supplementary, so
S = 120o and QSA = RSA = 60o
Now, PA = PQ cos 30o and OA = OQ sin 30o =
AS = OA = and PA = PO + OA = r +
Hence, PQ =
n=
n=
n=
n = 36 months
n = 3 years
or
or n =
or n = -303.66 months rejected.
As 'n' is no. of months here. So can't be -ve.
(ii) Let the mean proportional between (a4 - b4)2 and [(a2 - b2)(a - b)]-2 be x.
= = [ a2 + b2 - 2ab = (a - b)2]
cot = ...(ii)
or cot = ...(iii)
On adding Eqs. (i) and (ii), we get
cosec + cot = 2x
Now, adding Eqs. (i) and (iii), we get
cosec + cot =
Hence, cosec + cot = 2x or .
3. Question 3
(i) Given total height of the solid = 25 cm
Height of the cone (h2) = 4 cm
Diameter of the cylinder = 6 cm
Height of the cylinder (h1) = 25 - 4 = 21 cm
Radius of the cone = Radius of the cylinder = (r)
= = 3 cm
Slant height of cone =
=
=
= 5 cm.
i. Volume of the solid = Volume of cylinder + Volume of cone
=
=
=
=
= 631.71 cm3 632 cm3. (Approx.)
ii. Curved surface area of the solid = C.S.A of cylinder + C.S.A. of cone
= 2 rh1 + rl
= r(2h1 + l)
= 3(2 21 + 5)
= 3 47 = 443.14 cm2
Curved surface area = 443 cm2 (Approx.).
(ii) Given eqn of line y = 3x - 5
Comprare with y = mx + c we get.
Slope (m) = 3 and
y-intercept (c) = -5
Now slope of the line parellel to the given line will be 3 and it passes through (0, 5).
Thus eqn of line will be
y - y1 = m(x - x1)
y - 5 = 3(x - 0)
y - 5 = 3x
Y= 3x + 5
(iii)
i.
k2 < <k<
(iii) Class Frequency (f) x f
0-20 15 10 150
20-40 20 30 600
40-60 30 50 1500
60-80 a 70 70a
80-100 10 90 900
= 75 + a = 3150 + 70a
Given mean = 49
= 49
or, = 49
3150 + 70a = 3675 + 49a
70a - 49a = 3675 - 3150
21a = 525
a = 25
5. Question 5
(i) We know that two matrices are said to be equal if each matrix has the same number of rows and same number of
columns. Corresponding elements within each matrix are equal.
Given:
x + y = 5 ...(i),
2x - 3y = -5 ...(ii)
a - b = 3 ...(iii)
a + b = -1 ...(iv)
Solving eqn (i) and (ii)
y=3
Putting the value of y in eqn (i)
x+3=5
x=2
Again solving eqn (iii) and (iv)
a=1
Putting the value of a in eqn (iv)
1 + b = -1
b = -2
x = 2, y = 3, a = 1, b = -2
(ii)
150
146
142
Given that, In this manner, it took 8 more days to finish the work i.e. work finished in (n + 8) days.
+ ... + (n + 8) terms = 1
[150 + 146 + 142 + ... + (n + 8) terms] = 1
150 + 146 + 142 + ... +(n + 8) terms = 150n
Now a = 150 d = 146 - 150
= -4
diff. is equal It forms A.P.
Sn = [2a + (n - 1)d]
150 + 146 + 142 +.. (n = 8) terms = 150n becomes.
[2(150) + (n + 8 - 1)] = 150n
[150 - 2(n + 7)] = 150n
(n + 8)(150 - 2n - 14) = 150n
(n + 8)(136 - 2n) = 150n
136n - 2n2 + 1088 - 16n = 150n
2n2 - 120n - 1088 + 150n = 0
2n2 + 30n - 1088 = 0
n2 + 15n - 544 = 0
n2 + 32n - 17n - 544 = 0
n(n + 32) - 17(n + 32) = 0
(n + 32)(n - 17) = 0
n + 32 = 0 or n = 17
n = -32 n = 17
Reject n = -32 as n should be natural no.
n = 17 work was complete in 17 + 8 = 25 days.
7. Question 7
(i) Let the two digit no. be 10x + y
product of their digits
i.e., xy = 6
y = ...(i)
According to the question
10x + y + 9 = 10y + x
9x - 9y + 9 = 0
x - y = -1 ...(ii)
Substituting the value of y from equal (i),
= -1
= -1
x2 - 6 = -x
x2 + x - 6 = 0
x2 + 3x - 2x - 6 = 0
x(x + 3) - 2(x + 3) = 0
(x - 2)(x + 3) = 0
x = 2, x = - 3 (according to question rejected as digits are never negative)
put the value of x in eqn. (i)
y= =3
Thus, x = 2 and y = 3
Hence, the required no. = 10 2 + 3 = 23
(ii) C.I. f c.f
0 - 10 5 5
10 - 20 9 14
20 - 30 16 30
30 - 40 22 52
40 - 50 26 78
50 - 60 18 96
60 - 70 11 107
70 - 80 6 113
80 - 90 4 117
90 - 100 3 120
N = 120
i. Given, n = 120 which is even
Median = th term
= 60th term
Median = 43
ii. The number of students who obtained more than 75% marks in test = 120 - 110 = 10.
8. Question 8
(i) Let E and F denote the events that Niharika and Shreya win the match, respectively. It is clear that, if Niharika wins the
match, then Shreya losses the match and if Shreya wins the match, then Niharika losses the match. Thus, E and F are
complementary events.
P(E) + P(F) = 1
Since, probability of Niharika ’s winning the match, i.e. P(E) = 0.62
Probability of Shreya’s winning the match,
P(F) = P (Niharika losses the match)
= 1 - P(E)
= 1 - 0.62 = 038
(ii) Given:
h = 5m, d = 24 m, r = 12 m
l = 13 m
Convas Required = C.S.A of conical tent
= 87o
ii. (Alternate segment theorem)
iii. In = 180o (Sum of internal angles of a triangle = 180°)
9. Question 9
(i) i. A = {x : 3 < 2x - 1 < 9, x R}
3 < 2x - 1 < 9
3 + 1 < 2x - 1 + 1 < 9 + 1
4 < 2x < 10
2<x<5
A = (2, 5) R
B = {x : 11 3x + 2 23, x R}
11 3x + 2 23
11 - 2 3x + 2 - 2 23 - 2
9 3x 21
3 x 7
B = [3, 7] R
(ii) fi xi
Class Interval Required mid value
11 - 13 3 12 36
13 - 15 6 14 84
15 - 17 9 16 144
17 - 19 13 18 234
19 - 21 f 20 20f
21 - 23 5 22 110
23 - 25 4 24 96
= 704 + 20f
mean
18 =
720 + 18f = 704 + 20f
f=8
(iii)
x=
Hence we get the result x =
10. Question 10
(i) Let the present age of A and B are 7x and 8x respectively.
Then, 6 years ago their ages are 7x - 6 and 8x - 6
So,
6(7x - 6) = 5(8x - 6)
42x - 36 = 40x - 30
42x - 40x = -30 + 36
2x = 6
x= =3
Hence, the present age of A and B are 21 and 24.
(ii) i. Draw a circle with radius 6 cm and centre C.
ii. Take a point P at 10 cm from centre and join CP.
iii. Draw perpendicular bisector of CP which cuts CP at O.
iv. Take O as centre and OC as radius draw a circle which cuts the previous circle at A and B.
v. Join PA and PB.
vi. PA and PB are required tangents.
or y = ...(i)
In PQT,
tan 30o =
or x = ...(ii)
From eq. (i) and (ii), we get
x= = 16.66
= 17 m (correct to the nearest meter)