CBSE | NCERT CLASS

  Linear equation : The equation in which one variable present and highest degree is 1 is called linear equation in one variable.  Equation : An equation is a statement of equality of two algebraic expressions involving one or more   unknown quantities, called variables.    Rules   for solving a linear equation: i)  we can at the same number on both sides of the equation ii)  we can subtract the same number from both sides of the equation iii)  we can multiply both sides of the equation by the same non zero number iv)  we can divide both sides of the equation by the same non zero number. 1)  two numbers are in the ratio 5 : 4. Is the sum of the numbers is 207,find the numbers. 2) 3/4  of are number is 10 less than the original.  Find the number.  3) Five-sixth of a number is 20 more than three-fourths of the number. Find the number.  4) Thirty  is divided into two parts such that 6 times of the first part added to 2 4 times the second part makes 140. Find the numbers.  5) Find the numb

  1. Question Find the volume, lateral surface area and the total surface area of the cuboid whose dimensions are: (i) length = 22 cm, breadth = 12 cm and height = 7.5 cm Answer (i) We know that, Volume of cuboid = Length × Breadth × Height = (22 × 12 × 7.5) = 1980 cm3 We also know that, Total Surface Area of cuboid = 2 (lb + bh + hl) = 2 (22 × 12) + (22 × 7.5) + (12 × 7.5) = 2 (264 + 165 + 90) = 1038 cm² Now, Lateral surface area of cuboid = [2 (l + b) × h] = [2 (22 + 12) × 7.5] = 510 cm² (ii) length = 15 m, breadth = 6 m and height = 9 dm Answer: We know that, Volume of cuboid = Length × Breadth × Height = (15 × 6 × 0.9) = 81 m³ Total Surface Area of cuboid = 2 (lb + bh + hl) = 2 (15 × 6) + (15 × 0.9) + (6 × 0.9) = 2 (90 + 13.5 + 5.4) = 217.8 m² Lateral surface area of cuboid = [2 (l + b) × h] = 2 (15 + 6) × 0.9 = 37.8 m² (iii) length = 24 m, breadth = 25 cm and height = 6 m Answer: Volume of cuboid = Length × Breadth × Height = (24 × 0.25 × 6) = 36 m³ Total Surface Area of cuboid =

  The   surface area   is the   area   that describes the material that will be used to cover a geometric   solid . When we determine the   surface areas   of a geometric   solid   we take the sum of the   area   for each geometric form within the   solid . The   volume   is a measure of how much a figure can hold and is measured in cubic units. The  bodies that have a definite shape and volume are called solids.  The space occupied by a solid body is called its volume.   solid bodies occur in solid bodies occur in various shapes such as cuboids cubes cylinder cones and spheres.  Cuboid:  a solid bounded by six rectangular plane faces is called a cuboid.  Example: a matchbox, chalk box, a brick, a title,  a book. Cuboid has 6 rectangular faces, 12 edges, 8 vertices.   any face of any face of a cuboid maybe called its base.   the four faces which meet the base are the four faces which meet the base are called lateral faces of the cuboid.   6 faces are ABCD, EFGH,  EFBA, HGCD, EHDA, FGCB

 Quadrilateral CBSE NCERT Class (8, 9, 10) What is Quadrilateral? The closed figure bounded by four sides is called quadrilateral. It has four sides, four vertices and four angles. Sum of all angles is 360 degree. Example: ABCE is a quadrilateral. Its four vertices are A, B, C, D.  Its four angels are <ABC, <DAB, <BCD, <CDA. It has four sides AB, BC, CD, DA.

Area of a Trapezium, CBSE NCERT (Class 8, 9,10) Trapezium : A trapezium is a quadrilateral having one pair of parallel opposite sides.

Probability In our day-to-day life we here statements like: most probably it will rain today, chances are high that the prices of petrol will go up, I doubt that he will win the race. The words ‘most probably’, ‘chances’, ‘doubt’ show the probability of occurrence of an event. Experiment : An operation which can produce some well defined outcomes is called an experiment. Each outcome is called an event.

Factorisation Factors: When an algebraic equation can be written as the product of two or more expressions then each of these is called a factor of the give equation. Factorisation: The process of finding two or more expressions whose product is the given expression is called factorisation.

CBSE Worksheet-01 CLASS – VIII Mathematics (Direct and Inverse Proportions) Choose the correct option: 1. If 14Kg of pulses cost Rs441, what is the cost of 22 Kg of pulses? a. Rs 627       b. Rs 649 c. Rs 671       d. Rs 693