Revision-Problems


In these exercises the problems of moderate to hard sums are solved from all the chapters


R1 When 25% of the is a number is added to the number, then the resulting number is half of the number.

what is the original number?

Option:

A)200

B)150

C)100

D)300

Solution

Let the number be x

25% of the number=25x/100

25% 0f the number added to 25 is = 25x/100 +25

the resulting number is half of the number that is = x/2

Then 25x/100 +25 =x/2

multiply by 100 on both side of the above equation

then we will get

(25x/100) X 100 +(25×100)=(x/2)x100

25x100x/100 +2500=100x/2

25x+2500=50x

Re arrange we will get 50x -25x = 2500

simplify 25x=2500

divide 25 on both side

25x/25=2500/25

that is x=100

The Correct ANS=C

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R2 What Percentage 60 represent in relation to 300?

Option:

A)10

B)35

C)30

D)20

Solution:

Percentage = part/whole X100

part =60 and whole =300

therefore percentage=60/300 x100

simplify then we will get 20%

The correct ANS=D

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R3 In a right angled triangle the sides are 6√7,9√7 and √90 .

Find the are of the triangle.

Option:

A)180

B)185

C)189

D)165

Solution:

Area of the triangle =base x height/2 (formula for area of the Triangle)

Here base=9√7 and height =9√7

Area of the triangle=9√7×6√7/2=6x9x7/2=189 sq .units

Correct ANS:C

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R4 If 17/x=20 , What is the ratio of x/17?

Option :

A)1.05

B)0.05

0.06

D) 0.04

.

solution:

it is given 17/x=25multiply by x on both side

17/x Xx=25Xx17=25x divide by 25

17/25=25x/25 17/25=x divide by 171/25=x/17

x/17=1/25=0.04

Correct ANS:D

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SVG Circle with Arc O P Q 240

Q5 In a circle With center “O” and Angle P0Q measure 240.

What is degree measure of Are PQ ,that corresponds to the Angle POQ

Option,

A)120

B)220

c)320

D)420

Solution:

the angle measure POQ= 240 is the angle subtended by the Arc PQ at the center

The are PQ substance angle 240 at the center

measure of angle Arc PQ is half the angle sustained at the center ( circle and angles theorem)

therefore The Measure of angle PQ is = 1/2 x240=120

Correct ANS:A

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R6)The velocity of a vehicle is180 kilometers per hour. Convert in the velocity in meters per second.

We can write 180 kilometers per hour as 180kilometer/hour

Options:

A)50meterspersecond

B)40meterspersecond

C)60 meterpersecond

D)55 meterpersecond

Solution:

1 hour =3600 second and one kilometer=1000 meter

We can express 180 kilometer per hour as 180 X 1000/3600

Simplify we will get=50 meter per second.

CORRECT ANS:A

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R7) Area of a rectangle is 1500 squire units .the sides of the rectangles are in the ratio 5:3.

Find the diameter of the rectangle.

OPTIONS:

A)10√34 units

B)20√34 units

C)5√34 units

D)34 units

Solution :

Area of the Rectangle is =Length X breath =lXb

Here l and b are in the ratio 5:3

Let the length = 5x

And breath = 3x

Therefore Area of the Rectangles = 5xX3x=15x2 =1500 (given)

Divide both side by 15

That is 15/15 x2 =1500/15

x2=100

X=√100=10

Length of the rectangle= 5x=5X10=50

Breath of the rectangle =3x=3X10=30

Diagonal of the rectangle=√(502)+302=√3400=10√34 units

correct ANS:A

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R8)If the circle lies on XY-plan. And the center C(5 ,0) and end point of a radius is (9,-3).

Find the equation of the given circle.

solution:

We know thar equation of a circle with radius r and point of tne center ( a,b) is

(x-a)2+(y-b)2=r2

It is given the center point of the circle is (5.0)

Radius =r

Here it is given the center point (5,0) and end point of the radius (9,-3)

By applying two point equation for the length of a line=radius =√{(5-9)2+(0+3)2

=√16+9=√25=5

The equation of the circle with radius 5 and center point(5,0)

(x-5)2+(y-0)2=52

The equation is(x-5) 2+y2=25

ANS:(x-5) 2+y2=25

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R9) For the given -9x+my=22, Find the value of K If it has no solution? where m is content.

Solution:

the given equation is -9x+my=22

it is also given that ,the equation has nonsolution

so the equation should be worng by considering a value for the unknown constant

so we can assume that the value of m=9

by assuming m=9 the right hand side of the equation is = 0

therefore the equation become 0=22 that is not correct and it has no solution

Correct ANS: M=9

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R10)How many solution has the following quadratic equation y2=-49

Option:

A)one

2)None

3)many

D)two

Solution:

consider the given equation

y2=-49

so y=√-49/p>

it is complex number , so the given equation has no solution

Correct ANS:B

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R11)At what value of x does the function f(x)=2x2-36x-19 reaches its minimum point.

option:

A)1.5

B)-1.5

C)-3/4

D)3/4

Solution:

consider the given equation f(x)=2x2-6x+15

It is a quadratic equation

for a general quadratic equation f(x)=ax2+bx+c

minimum value of a quadratic equation occurs at x= -b/2a ( fomula) in the given equation b=-6 and a=2

substitute the values of a and b in the formula x=-b/2a

we will get x=-(-6)/2X2

that is x=6/4=3/2 =1.5Correct ANS:A

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R12)Find the vale of 3x(2x-1),the value of x from the given equation

5(x-1)+5x=30

Option:

A)24

B)-24

C)14

D)-14

Solution:

consider the given expression 5(x-1)+5x=30

take common out for the left side of the Expression

now we will get 5x(5-1+1)=30

That is 5x(1/5+1)=30

now 5x(6/5)=30 (simplify)

5x=30X5/6

5x=5X5 (simplify)

5x=52

compare the powers ,because the the basis are the same by exponential lawwe will get the value of x=2

now substitute the value of x=2 in the given equation

that is 3x(2x-1)

now we will get 3X2(2X2-1)

That is 3X23

3X8=24

Correct ANS:24

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RQ12 Find the angle value of angle NMB from The given diagram.

The angle B is right angle

Right-Angled Triangle SVG A B C X Z M N 25 55

solution:

Consider the ∆ ABC

Sum of three angles ∠CAB+∠ABC+∠ACB=180 ( property of triangle sum of three angles)

∠CAB+90+55=180

∠CAB+145=180∠CAB=180-145=35

Consider the ∆ XAN .

∠XNA=∠CNM (AB and XZ intersects at N, Opposite angle is equal)

∠XNA=25 ( ∠ CNM=25 9given) in the ∆XNA ,∠NAB=∠ANX+∠NXA ( exterior angle is equal to sum of opposite angles

that is 35=25+∠NXA

35 – 25 =∠NXA

MBX=180

now consider the ∆XMB

∠MXB+∠XMB+∠MBX=180 (properties of triangle)

10+90+∠XMB=180

∠XMB+100=180

simplify then we will get ∠XMB=180-100

Therefore ∠XMB=80

Correct ANS: ∠XMB=80

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RQ13 Find the value of angle∠OAX= y in the dia gram

in the given diagram O is the center of the circle

AB is the chord, X is a point on the circle

it is also given ∠OXB=55 degree

Circle with Diameter and Angles O A B X 55° Y

Solution:

Consider the ∆ AOC

∠OAB=55° (given)

∠XBO= ∠ OXC (angle opposite equal sides of the triangle )

Now consider ∆XOB

∠ OXB+ ∠XOB+ ∠OBX=180 (Sum of three angles in a triangle)

55+ ∠XOB+55 =180

110+ ∠XOB=180

add -180 on both side of the equation

110-110+ ∠XOB=180-110

∠XOB=70

Now consider the ∆XAO, ∠ XOB = ∠AXO+ ∠ XAO

Here ∠ XOB is the exterior angle of the triangle XAO

∠AXO+ ∠ XAO =70

But ∠AXO and ∠ XAO are equal (angle opposite to equal sides

∠ XAO =70/2=35

Correct ANMS= 35°

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RQ 14 In the given diagram O is the center of the circle. and AB is a diameter of the circle

AT is a tangent at point A on the circle. if the Angle AOM is 68° .Find the value angle ATM

Option:

A)44°

B)24°

C)56°

D)45°

Circle Geometry – SVG O A B T M

Solution

In The diagram it is given ∠AOM= 68°

that is The arc MB of the given circle subtends ∠MOA at the center of the circle

∠ ABM is the angle subtends by the Arc AM on the circumference of the circle

therefore ∠ABM = 1/2∠AOM=68/2=34Now consider the ( by circle theorem)

Now consider the ∆ABT, AB is the diameter and AT is the tangent through the point A

Therefore ∠ TAB=90° (Properties of tangents and circle)

We know the ∠ ABT= 34°

Sum three Bangles in the ∆ABT is 180°

That is ∠ABT+∠TAM+∠ATB=180°

34°+90°+∠ATM=180°

124° + ∠ ATM=180°

Add -124 on both side of the equation

124°-124°+∠ATM =180°-124

therefore ∠ATM=56°

Correct ANS: C

RQ15) Find the degree measure of angle x in the given diagram

SVG Circle with Points and Lines A C B F D E 102 32 x

solution

Consider the ∆CDB in the above diagram

∠ ADC=∠ DBC+∠DCB=42+∠DCB (Exterior angle is equal to sum of inferior opposite angles in a triangle)

∠FAD=∠ DCF (angle subtended by the arc DF at A and C properties of circle)M

therefore ∠DCF= x

Therefore exterior ∠ADC=x+42

Now consider ∆AED

x+∠AED+∠ADE=180 (sum of three angles in a Triangle)

But ∠ADE=x°+42 (proved)

Now consider the Stright line DC

∠AEC+ ∠AED=180 (Propeties of Stright line)

But ∠AEC= 94 (given)

therefore 94+∠AED=189

add -94 on both side

94-94+∠AED=180-94

∠AED=86

substitute the value of ∠AED=86 in sum of angle in the Triangle AED

and substitute the value of ∠ADE=x+42 (proved )

therefore sum of three angles in the Triangle ADE

becomes x+x+42+86=180

That is 2x+128=180 (simplified)

Add -128 on both side, then we will get

2×128-128=180-128

2x=52 (simplyfied)

divide by 2 on both side, Then we will get

2x/2= 52/2

x=26>

Correct ANS:26°

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RQ16) Find the area of the Trapezium with parallel sides 120 and 90 withstanding side 25

Trapezium with SVG

Trapezium with parallel sides 240and 180, slanting sides50

A B C D E 120 90 25

solution:

From the diagram ABCD is isoceless trapeziam

Because the slanding sides AD=CB

Area of the trapeziam = 1/2(sum of parallel sides )X height

where th height of the trapezium is the distance between the parallel sides

To find the height of the trapezium

Consider the ∆AED

AD=25 and AE=AB-CD/2=(120-90)/2 ( properties of Isoceles Trapezium)

That is AE=30/2=15

∆AED is right angled triangke

By Phyrhagoras theoram AD2=AE2+ED2

sustitutes AD=25 and AE=15

Then we will get 252=AE2+152

625=225+AE2

Simplify AE2=625-225

AE2=400

AD=√4oo

That is AE=Height=20

Area of the trapezium =1/2(sum of parallelsides)Xheight

Area of the Trapezium =1/2(120+90)X20=2100 squire units

Correct ANS:=2100 squire units<

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RQ17) find the length measure of Tangent to the smaller circle in the given diagram

It is also given the radius of the lager circle and the radius of the smaller circle are

27 units and 9 units respectively and a tangent is drawn for a point lies out side the circles

to the larger circle is 36 units.

Options:

A)12 units

B)9 units

C)22 units

D)14 units

Two Touching Circles and Tangents P Q R T S O C SP=x QP=36 OQ=27 CS=9

From The diagram QO=27 units and CS=9 units ( Radii of the circles)

QP is a tangent to the larger circle and its measure is 36 units

Now consider the ∆ CSP and ∆OQP

∠OQP = ∠CSP and ∠QPO= ∠SPC (Caman angle)

so ∆CSP and ∆QOP are similar < By angle property of similarity)

In a similar Triangle the corresponding sides are in the same ratio

That is sp/QP=CS/QO

by substituting the values for SP=x ,QP=36 units ,CS=9 units and QO=27 units

Now x/36=9/27

Multiply by 36 on both side

we will get xX36/36 =9X36/27

simplify x=12 units

Correct ANS: A

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Circle with Chord and Tangent O A B C Tangent Trapezium Drawing

Trapezium with Parallel Sides 120 and 240, Slanting Side 149 and 139

A B C D E F Top = 120 Bottom = 240 Side = 149 Side = 139

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RQ19) Find ∠ACB in the given diagram.

Options:

A)65

B)65

C)75

D)95

Triangle with Point M and Angles A B C M 2y 2x x y 110

Consider The ∆AMB

By the properties of Triangle sim of three angles in a triangle is 180

that is ∠ABM + ∠ BAM + ∠ AMB =180

in the diagram it is given ∠MAB=2y, ∠AMB=110 and ∠ MBA=2x

Therefore 2x+2y+110=180

Add -110 in the above equation

Now we will get 2x+2y+110-110=180-110

2x+2y=70

divide both side of the above equation by 2

That is 2x/2+2y/2=70/2

x+y=35

Now consider the quadrilateral CBMA

∠AMB =110 is the exterior angle at M of the Quadrilaterals CBMA

By the properties of a quadrilateral the exterior angle at any point is equal to sum the three interior angles

Here Interior angles sum is ∠ ACB + ∠CAM+ ∠CBM =110

Substitute the value of ∠CAM= x and ∠ CBM= y

Therefore the above equation becomes ∠ ACB+x+y=110

But we proved x+y=35

Now substitute the value of x+ y=35 in the above equation

Therefore 35+ ∠ACB=110

Add -35 0n both side

35-35+ ∠ACB =110-35

∠ACB=75

Correct ANS:C

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RQ20)

Circle with Chord O r=50 AB=80 A B

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RQ21

Quadrilateral PQRS (SVG) P Q R S 70

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