DPS-MODERN INDIAN SCHOOL, DOHA-QATAR
SA- 2 REVISION ASSIGNMENT ( 2014-’15)
MATHEMATICS- CLASS VIII
CH: 9 -ALGEBRAIC EXPRESSIONS AND IDENTITIES
1. Use suitable identity to find the following.
i. ( 7p + 8q) ( 7p − 8q)
ii. ( 3a + 4b) ( 3a + 4b)
iii. (5x – 7y) (5x + 3y)
iv. (3𝑒 − 2𝑓) (3𝑒 − 2𝑓)
v. 205 × 195
vi. (103)2
vii. (199)2
viii. ( 2𝑠 +7 𝑡)2− ( 2𝑠 −7 𝑡)2
2. Find the product:
i. 4d ( 3d + 8e)
ii. (3r + 8s) ( 5r + 9s)
iii. p ( 3p + 4q−5𝑟)
iv. (7a+ 2b+ 5c) ( 11 a + 4b)
3. Subtract the sum of 2m( 3m – 5𝑛) 𝑎𝑛𝑑 3𝑚2+7𝑚𝑛 𝑓𝑟𝑜𝑚 3𝑚 (5𝑛−2𝑚)
4. Add: 4g + 9h −5𝑖, 8𝑔+9𝑖−4ℎ 𝑎𝑛𝑑 2𝑔−11ℎ−3𝑖
5. Simplify 3( p+ 4q) − 6( 2𝑝+𝑞)+(3𝑝+2𝑞) and find its value for p = 3 and q = − 2
6. Show that (2a +5b)2−40𝑎𝑏=( 2a−5b)2
CH: 14 -FACTORISATION
I.
Factorise the following
1.
2.
3.
4.
5.
6.
7.
II.
12x2 - 8x + 3xy - 2y
5x2yz - 40xy3 + 20x3
3a2 - 12a - 63
12x5 - 108x3
9a2 - 12ab + 4b2
a2 - 6ab + 9b2 - c2
p2 - 4m2 + 20mn - 25n2
Divide the following.
1. 9p3q - 12p3q3 + 6q2 by 3q
2. 9m2 - 81n2 by 3m + 9n
3. 28x - 21y + 8x2 - 6xy by (4x - 3y)
CH:13 -DIRECT AND INVERSE PROPORTION
1)The length of the side of any square is:
a) in direct proportion to the area of the square.
b)in inverse proportion to the perimeter of the square.
c) in inverse proportion to the area of the square.
d) in direct proportion to the perimeter of the square.
2) A private taxi charges a fare of ₨260 for a journey of 200km. How much
would it travel for ₨ 279.50?
3) In a nursing home, there are 50 glucose bottles sufficient for 40 patients. If 20
more patients are admitted to the hospital, how many more bottles have to be
ordered?
4) If 6 men can do a piece of work in 7 days, how many days will it take for 21
workers to finish it?
5) If x and y are inversely proportional to each other and x = 3, y = 8, then find y
when x = 4.
6) Raja bought 12 register for Rs156.Then the cost of 7 such registers is
a) 71
b) 81
c) 91 d) 61
7 ) Find a and b if x and y vary directly
x
y
7
21
9
a
13
39
b
63
8) 15 stamps of equal value cost Rs18 .How many stamps of the same value can
be brought for Rs36?
9) An electric pole 14 meters high, casts a shadow of 10 meters. Find the height of
a tree that casts a shadow of 15 meters under similar conditions.
10) A Factory requires 42 machines to produce a given number of articles in 63
days .How many machines would be required to produce the same number of
articles in 54 days?
CH:8 -COMPARING QUANTITIES
1) A student buys a pen for Rs 90 and sells it for Rs 100. Find his gain and
gain percent.
2) Find the ratio of :
a) 10m to 20km b) 25 paise to Rs 5
3)Find the discount in percent when
a)Marked price =Rs 625 and Sale price =Rs 562.50
b)Marked price =Rs 1600 and Sale price =Rs 1180
4) At a clearance sale all goods are on sale at 45% discount. If marked price of a
skirt is Rs 600, how much would be its sale price?
5) George bought a V.C.R at the list price of Rs 18,500. If the rate of VAT was
8%, find the amount he had to pay for purchasing the VCR.
6) The price of a T.V set inclusive of VAT is Rs 13,530.If the rate of VAT is 10%,
find its basic price.
1
7) Find the compound interest on Rs 1000 at the rate of 8% per annum for 1
2
years when interest is compounded half yearly.
8) What will be the compound interest on Rs 4000 in 2 years and 4 months when
the rate of interest is 5% per annum compounded annually.
9)Roma borrowed Rs 64000 from a bank to purchase a T.V .If the rate of interest is
1
2 % per annum compounded half yearly, calculate the compound interest that
2
Roma has to pay to the bank after 6 months.
1
10) Swati took a loan of Rs 16000 against her insurance policy at rate of 12 %
2
per annum. Calculate the compound interest paid by Swati after 3 years.
FORMULAE:
* Profit =SP- CP
* Loss=CP –SP
* Profit %=( Profit x 100) ÷ CP
* Discount = Marked price - Sale price
* Discount%= (Discount x100) ÷ Marked price
* Discount= (Discount% x Marked price) ÷ 100
* Bill amount= Cost of item + Sales Tax
*S.I = PRT ÷ 100
where P-principal, R-rate of interest, T-time period
*Amount=P + S.I
𝑅
*A =P(1+
)n ,if interest is compounded annually. Where P- principal, R- rate
100
of interest, n- time period, A- amount.
*A= P(1+
𝑹 2n
)
200
* C.I =A-P
if interest is compounded half yearly.
CH: 15 - INTRODUCTION TO GRAPHS
1) Write the co-ordinates of the vertices of each of the following figures
2) Plot the given point in a graph sheet and verify whether they lie on a line
a) A (2,3), B (0,1), C (4,5)
b) P (5,7), Q (3,5), R (2,3), S (0,3)
3) Draw a line passing through (1,6) and (3,2). Find the co-ordinates of the points
at which this lines meets the X- axis and Y- axis
CH: 4 - PRACTICAL GEOMETRY
1) Construct a quadrilateral ABCD in which AB = 4.5cm, BC=5.2cm,
CD=4.8cm, AD=5cm, and AC= 6.5cm.Write steps of constructions.
2) Construct a quadrilateral PQRS in which PQ=5cm, QR=6cm, SR = 5.5cm,
diagonal PR=4cm and diagonal SQ=9.5cm. Write steps of constructions
3) Construct a quadrilateral FISH in which FI=5cm, IS=4.6 cm, SH=3.1cm,
∠I = 750 , ∠ S=1200.Write steps of constructions
4) Construct a rectangle NEAR, given that NE=3.5cm, EA=4cm and NA=6cm.
5) Construct a rhombus whose diagonals are of length 5cm and 7.3cm
6) Construct a square each of whose diagonals are 6.8cm
7) Construct a Parallelogram PQRS, given that PQ= 4cm, QR=5.7cm, ∠ Q=750
Chapter – 11 MENSURATION
1) A square field of side 50m and a rectangular field of length 60m have the same
perimeter. Which field has a larger area?
2) The area of a quadrilateral shaped field is 252 m2. The perpendiculars dropped
on that diagonal from the opposite corners are 8 m and 13 m. Find the length of
the diagonal.
3) A swimming pool is 25 m in length, 20 m in breadth and 5 m in depth. Find the
cost of cementing its floor and walls at the rate of Rs 36 per square metre.
4) Find the height of a trapezium whose area is 65 cm2 and whose parallel sides
are 13 cm and 26 cm.
5) Find the volume of a cube whose surface area is 54 cm2.
6) Find the volume, the area of curved surface and the total surface area of a
cylinder whose height is 40 cm and radius of the base 3.5 cm.
7) The curved surface area of a cylinder is 1320 cm2 and its base has diameter 21
cm. Find the height and volume of the cylinder.
8) The area of a rhombus is 240 cm2 and one of the diagonals is 16 cm . Find the
other diagonal.
9) Outer surface of a cylindrical vessel, with lid, has to be tin-coated. If the radius
of the base is 70 cm and its height is 1.4 m, calculate the cost of tin-coating at
the rate of Rs 3.50 per 1000 cm2.
10) A closed iron tank 12 m long, 9 m wide and 4m deep is to be made.
Determine the cost of iron sheet required at the rate of Rs 5 per m2.
CH: 10- VISUALISING SOLID SHAPES
1. Write Euler’s formula for polyhedrons.
2. A polyhedron has 6 vertices and 12 edges. Find the number of faces it has.
3. Can a polyhedron have 12 faces, 25 edges and 15 vertices?