MATHS ASSIGNMENT CLASS 8 (DIRECT AND INVERSE , MENSURATION ,ALGEBRIC EQUATION )

            MATHS ASSIGNMENT CLASS 8

Direct and Inverse Proportions Class 8 Extra Questions Very Short Answer Type

Question 1.
A train is moving at a uniform speed of 100 km/h. How far will it travel in 20 minutes?
Solution:

Question 2.
Complete the table if x and y vary directly.

Question 3.
If the cost of 20 books is ₹ 180, how much will 15 books cost?

Question 4.
If x1 = 5, y1 = 7.5, x2 = 7.5 then find y2 if x and y vary directly.

Question 5.
If 3 kg of sugar contains 9 × 108 crystals. How many sugar crystals are there in 4 kg of sugar?

Question 6.
If 15 men can do a work in 12 days, how many men will do the same work in 6 days?

Question 7.
A train travels 112 km in 1 hour 30 minutes with a certain speed. How many kilometres it will travel in 4 hours 45 minutes with the same speed?

Question 8.
The scale of a map is given as 1 : 50,000. Two villages are 5 cm apart on the map. Find the actual distance between them.

Question 9.
8 pipes are required to fill a tank in 1 hr 20 min. How long will it take if only 6 pipes of the same type are used?

Question 10.
15 men can build a wall in 42 hours, how many workers will be required for the same work in 30 hours?

Mensuration Class 8 Extra Questions Very Short Answer Type

Question 1.
Find the perimeter of the following figures:

Question 2.
The length and breadth of a rectangle are 10 cm and 8 cm respectively. Find its perimeter if the length and breadth are (i) doubled (ii) halved.

Question 3.
A copper wire of length 44 cm is to be bent into a square and a circle. Which will have a larger area?

Question 4.
The length and breadth of a rectangle are in the ratio 4 : 3. If its perimeter is 154 cm, find its length and breadth.

Question 5.
The area of a rectangle is 544 cm2. If its length is 32 cm, find its breadth.

Question 6.
If the side of a square is doubled then how much time its area becomes?

Question 7.
If the lengths of the diagonals of a rhombus are 16 cm and 12 cm, find its area

.Question 8.

The area of a rhombus is 16 cm2. If the length of one diagonal is 4 cm, find the length of the other diagonal.

                                                                        Question 9.
If the diagonals of a rhombus are 12 cm and 5 cm, find the perimeter of the rhombus.

                                                                    Question 10.
The volume of a box is 13400 cm3. The area of its base is 670 cm2. Find the height of the box.

Algebraic Expressions and Identities

Question 1.
Write two examples of each of
(i) Monomials
(ii) Binomials
(iii) Trinomials

Question 2.
Identify the like expressions.
5x, -14x, 3x2 + 1, x2, -9x2, xy, -3xy

Question 3.
Identify the terms and their coefficients for each of the following expressions:
(i) 3x2y – 5x
(ii) xyz – 2y
(iii) -x – x2

Question 4.
Add: -3a2b2, –52 a2b2, 4a2b2, 23 a2b2

Question 5.
Add: 8x2 + 7xy – 6y2, 4x2 – 3xy + 2y2 and -4x2 + xy – y2

Question 6.
Subtract: (4x + 5) from (-3x + 7)

Question 8.
Multiply the following expressions:
(a) 3xy2 × (-5x2y)
(b) 12 x2yz × 23 xy2z × 15 x2yz

Question 9.
Find the area of the rectangle whose length and breadths are 3x2y m and 5xy2 m respectively.

Question 10..
Multiply (3x2 + 5y2) by (5x2 – 3y2)

Question 11.
Multiply (6x2 – 5x + 3) by (3x2 + 7x – 3)

Question 12..
Using suitable identity find:
(i) 482 (NCERT Exemplar)
(ii) 962
(iii) 2312 – 1312
(iv) 97 × 103
(v) 1812 – 192 = 162 × 200

Question 13.
Find the value of 382−22216, using a suitable identity. 

Exponents and Powers Class 8 Extra Questions Maths Chapter 12

Question 1.
Find the multiplicative inverse of:
(i) 3-3
(ii) 10-10

Question 2.
Expand the following using exponents.
(i) 0.0523
(ii) 32.005

Question 3.
Simplify and write in exponential form.

Question 4.
Simplify the following and write in exponential form.

Question 5.
Simplify the following and write in exponential form.
(i) (36 ÷ 38)4 × 3-4
(ii) 127 × 3-3

    

Question 6.

Find the value of k if (-2)k+1 × (-2)3 = (-2)7

Question 7.
Simplify the following:

Question 8.
Find the value of [(−34)−2]2

Question 9..
Find the value of P if

Question 10..