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ALGEBRA
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Time: 2 ½ Hours
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MARCH 2000
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Marks: 75
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| Q.1. |
Attempt any five of the following:
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10 |
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i)
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If
2x + 5y = 1 and 5x + 2y = 13, find the values of 7x + 7y
and 3x + 3y.
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ii)
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The
side of an equilateral triangle is 7 cm. Find its perimeter.
Write down the ratio of its side to its perimeter.
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iii)
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If
x µ
and x = 15 when y = 3, find y when x = 9.
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iv)
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If
3 sin q = 4 cos q, find the value of tan q.
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v)
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Write the equation r2 - r = 2r -5 in
the form of ax2 + bx + c = 0 and then write the
value of a, b and c.
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vi)
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If
cot A = , then find the value of cosec A.
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vii)
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Verify whether the expression (a-b) (c-b) (a-c)
is cyclic.
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Q.2.
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Attempt any five of the following:
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15
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i)
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Points (3,0) and (0,4) are on a line having equation
Ax + By = 12.
Find the values of A and B.
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ii)
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If
a natural number is added to its square, the sum is 56,
find the number.
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iii)
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If
,
then find the value of .
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iv)
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Weekly Income
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Frequency |
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200-300
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25 |
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300-400
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60 |
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400-500
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80 |
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500-600
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30 |
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600-700
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10 |
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700-800
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15 |
Draw
a histogram of the data. (Scale: 1 cm = 10)
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v)
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Show
that:
(sin
x + cosec x) 2 + (cos x + sec x) 2 =
tan2x + cot2 x +7.
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vi)
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Find
the order relation between .
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vii)
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A
piece of string 12 m in length was cut into pieces such
that one piece is x metre and other is y metre.
If y is 2 metres more than x, find the length
of each piece.
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| Q.3. |
a)
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Solve any two of the following:
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6
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i)
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The
force of the attraction between two unlike magnetic poles
varies inversely as the square of the distance between them.
If the distance is 9 cm, then the force of attraction is
4 dyne. Find the force of attraction if the distance between
the poles is 3 cm.
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ii)
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Solve: x2 + 4x - 5 = 0
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iii)
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Show
that
+ cos A = sec A
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b)
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Solve any one of the following:
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4
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i)
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Solve: 23a - 25b = 215,
25a
- 23b = 217
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ii)
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If
a, b, c are in continued proportion, show that .
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| Q.4. |
a)
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Solve any two of the following:
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6
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i)
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Using formula, find factors of x2 +
8x + 7.
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ii)
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Solve: x + 6y = 22,
+ y = 4.
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iii)
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The
marks obtained by 40 students in a class are given below:
35,
15, 29, 40, 31, 07, 40, 11, 48, 01, 45, 03, 32, 43, 49,
18, 30, 24, 25, 29, 23, 12, 25, 09, 27, 41, 12, 13, 02,
44, 30, 48, 22, 49, 19, 13, 32, 39, 25, 03
Prepare a grouped frequency table.
(Take classes 1-10, 11-20, &..)
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b)
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Attempt any one of the following:
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4
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i)
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Take
1 cm = 1 unit on both axes. Draw graph of y = x 1 and
2y = -x + 2 on the same graph paper. Write the coordinates
of the point of intersection of the graphs.
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ii)
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Observe the given table and answer the questions
below it:
Class (Age Group) :
1-7 8-14 15-21
22-28
Frequency
: 105 315
208
331
(No. of Persons)
1. Write the interval and the mid-point
of the class 15-21.
2. Write true upper and true lower limil of class
22-28.
3. How many persons are of the age below 22 years?
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Q.5.
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Attempt any three of the following:
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15
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i)
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Factorise: (x + y + z) 3 -x3
-y3 - z3.
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ii)
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A
number formed by two digits exceeds the number formed by
reversing the digits by 18, and three times the product
of the digits exceeds five times the sum of the digits by
5. Find the number.
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iii)
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The
following table shows percentage population of some nations
with respect to the world population. Draw a pie-diagram
representing the information. (Round off the measures of
arcs of sectors, if necessary, to the nearest integer.)
Nations :
A B C
D Other
Nations
Percentage :
5 6 15
22 52
Population
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iv)
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Draw
the graph of the following equations on the same coordinate
system:
1) 4x + 3y = 18,
2) x + y = 5, 3) x = 5. State with reason, whether
the graphs are concurrent.
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Q.6.
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Attempt any three of the following:
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15
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i)
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The
distance of horizon seen from a spot varies directly as
the square root of the height of the spot. When a person
descended 300 metres from a spot at a certain height, the
distance of horizon appeared half of the original. When
he further descended 19 metres more, the distance of horizon
was 1.1 kilometer. Find the height of the spot where he
was standing originally and the distance of horizon appeared
to him from there.
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ii)
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A
medicine has four ingredients A, B, C and D. The ratio of
the masses of A and B is 3:2. The mass of C is 50% of B
and the mass of D is
of the mass of C. Find the mass, in milligrams, of each
ingredient in a tablet of mass 1 gram.
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iii)
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Solve:
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iv)
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For
acute angles A and B, the following relations are given
to be true:
sin
A > cos A, sin B < cos B
State with reasons, which of the following relations
are true:
- sin (A - B) > cos (A - B)
- tan A > tan B
Further, if sin (A + B) = 1,
find the value of sin A cos B + cos A sin B.
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