ICSE Books Solutions

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 7 Percent and Percentage Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 7 Percent and Percentage Percent and Percentage Exercise 7A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Evaluate : (i) 55% of 160 + 24% of 50 – 36% of 150 (ii) 9.3% of 500 – 4.8% of 250 – 2.5% of 240 Solution: Question 2. (i) A number is increased from 125 to 150 ; find the percentage increase. (ii) A number is decreased from 125 to 100 ; find the percentage decrease. Solution: Question 3. Find : (i) 45 is what percent of 54 ? (ii) 2.7 is what percent of 18 ? Solution: Question 4. (i) 252 is 35% of a certain number, find the number. (ii) If 14% of a number is 315 ; find the number. Solution: Question 5. Find the percentage change, when a number is changed from : (i) 80 to 100 (ii) 100 to 80 (iii) 6.25 to 7.50 Solution: Question 6. An auctioneer charges 8% for selling a house. If a house is sold for Rs.2, 30, 500; fin

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 6 Sets Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 6 Sets Sets Exercise 6A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Write the following sets in roster (Tabular) form :   Solution:         Question 2. Write the following sets in set-builder (Rule Method) form :   Solution:   Question 3. (i) Is {1, 2, 4, 16, 64} = {x : x is a factor of 32} ? Give reason. (ii) Is {x : x is a factor of 27} ≠ {3, 9, 27, 54} ? Give reason. (iii) Write the set of even factors of 124. (iv) Write the set of odd factors of 72. (v) Write the set of prime factors of 3234. (vi) Is {x : x2 – 7x + 12 = 0} = {3, 4} ? (vii) Is {x : x2 – 5x – 6 = 0} = {2, 3} ? Solution: (i) No, {1, 2, 4, 16, 64} ≠ {x : x is factor of 32} Because 64 is not a factor of 32 (ii) Yes, {x : x is a factor of 27} + {3, 9, 27, 54} Because 54 is not a factor of 27 (iii) 1 x 124 = 124 2 x 62 = 124 4 x 31 = 124 Factors of 124 = 1, 2, 4, 31, 62,

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 5 Playing with Number Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 5 Playing with Number Playing with Number Exercise 5A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Write the quotient when the sum of 73 and 37 is divided by (i) 11 (ii) 10 Solution: Question 2. Write the quotient when the sum of 94 and 49 is divided by (i) 11 (ii) 13 Solution: Question 3. Find the quotient when 73 – 37 is divided by (i) 9 (ii) 4 Solution: Question 4. Find the quotient when 94 – 49 is divided by (i) 9 (ii) 5 Solution: Question 5. Show that 527 + 752 + 275 is exactly divisible by 14. Solution: Property : abc = 100a + 106 + c ………(i) bca = 1006 + 10c + a ……..(ii) and cab = 100c + 10a + b ……….(iii) Adding, (i), (ii) and (iii), we get abc + bca + cab = 111a + 111b + 111c = 111(a + b + c) = 3 x 37(a + b + c) Now, let us try this method on 527 + 752 + 275 to check is it exactly divisible by 14 Here, a = 5, 6 =

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 4 Cubes and Cube-Roots Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 4 Cubes and Cube-Roots (Including use of tables for natural numbers) Cubes and Cube-Roots Exercise 4A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Find the cube of : (i) 7 (ii) 11 (iii) 16 (iv) 23 (v) 31 (vi) 42 (vii) 54 Solution: (i) (7)3 = 7 x 7 x 7 = 343 (ii) (11)3 =11 x 11 x 11 = 1331 (iii) (16)3 = 16 x 16 x 16 = 4096 (iv) (23)3 = 23 x 23 x 23 = 12167 (v) (31)3 = 31 x 31 x 31 = 29791 (vi) (42)3 = 42 x 42 x 42 = 74088 (vii) (54)3 = 54 x 54 x 54 = 157464 Question 2. Find which of the following are perfect cubes : (i) 243 (ii) 588 (iii) 1331 (iv) 24000 (v) 1728 (vi) 1938 Solution: 1938 = 2 x 3 x 17 x 19 1938 is not a perfect cube. Question 3. Find the cubes of : (i) 2.1 (ii) 0.4 (iii) 1.6 (iv) 2.5 (v) 0.12 (vi) 0.02 (vii) 0.8 Solution: Question 4. Find the cubes of : (i)  (ii)  (iii)  (iv)  (v)  Solution: Question 5. F

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 3 Squares and Square Roots Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 3 Squares and Square Roots Squares and Square Roots Exercise 3A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Find the square of : (i) 59 (ii) 63 (iii) 15 Solution: (i) Square of 59= 59 x 59 = 3481 (ii) Square of 6.3 = 6.3 x 6.3 = 39.69 (iii) Square of 15 = 15 x 15 = 225 Question 2. By splitting into prime factors, find the square root of : (i) 11025 (if) 396900 (iii) 194481 Solution: Question 3. (i) Find the smallest number by which 2592 be multiplied so that the product is a perfect square. (ii) Find the smallest number by which 12748 be mutliplied so that the product is a perfect square? Solution: On grouping the prime factors of 2592 as shown; on factor i.e. 2 is left which cannot be paired with equal factor. The given number should be multiplied by 2 to make the given number a perfect square. On grouping the pri

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 2 Exponents (Powers) Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 2 Exponents (Powers) Exponents Exercise 2A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Evaluate: Solution: Question 2. If 1125 = 3m x 5n; find m and n. Solution: Question 3. Find x, if 9 × 3x = (27)2x-3 Solution: Exponents Exercise 2B – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Compute: Solution: Question 2. Simplify: Solution : Question 3. Evaluate: Solution: Question 4. Simplify: Solution: Question 5. Simplify: (xa+b)a-b.(xb+c)b-c.(xc+a)c-a Solution: Question 6. Simplify: Solution: Question 7. (i) (a-2)-2. (ab)-3 (ii) (xny-m)4 × (x3y-2)-n Solution: Question 8. Show that: Solution: Question 9. Evaluate: Solution: Question 10. Evaluate: Solution: Question 11. (m+n)-1 (m-1 + n-1) = (mn)-1 Solution: Question 12. Prove that: Solution: Question 13. Find the values of n, when: Solution: Question 14. Simpli

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers Rational Numbers Exercise 1A – Selina Concise Mathematics Class 8 ICSE Solutions Question 1. Add, each pair of rational numbers, given below, and show that their addition (sum) is also a rational number:    Solution:             Question 2. Evaluate:   Solution:             Question 3. Evaluate:   Solution:           Question 4. For each pair of rational numbers, verify commutative property of addition of rational numbers:    Solution:   This verifies the commutative property for the addition of rational numbers.     This verifies the commutative property for the addition of rational numbers.     This verifies the commutative property for the addition of rational numbers.   This verifies the commutative property for the addition of rational numbers.   This verifies the commutative property for the addition of rational numbe

Selina Concise Mathematics Class 8 ICSE Solutions 2019-20 Selina Concise Mathematics Class 8 ICSE Solutions THEME – 1 NUMBER SYSTEM 1. Rational Numbers 2. Exponents (Powers) 3. Squares and Square Roots 4. Cubes and Cube-Roots (Including use of tables for natural numbers) 5. Playing with Number 6. Sets THEME – 2 RATIO AND PROPORTION 7. Percent and Percentage 8. Profit, Loss and Discount 9. Simple and Compound Interest 10. Direct and Inverse Variations THEME – 3 ALGEBRA 11. Algebraic Expressions (Including Operations on Algebraic Expressions) 12. Algebraic Identities 13. Factorisation 14. Linear Equations in one Variable (With Problems Based on Linear equations) 15. Linear Inequations (Including Number Lines) THEME – 4 GEOMETRY 16. Understanding Shapes (Including Polygons) 17. Special Types of Quadrilaterals 18. Constructions (Using ruler and compass only) 19. Representing 3-D in 2-D THEME – 5 MENSURATION 20. Area of Trapezium and a Polygon 21. Surface Area, Volume and Capacity (Cuboid,

Selina Concise Mathematicsclass 6 ICSE Solutions – Data Handling (Including Pictograph and Bar Graph) Selina Concise Mathematicsclass 6 ICSE Solutions – Data Handling (Including Pictograph and Bar Graph) IMPORTANT POINTS The word statistics is used for two different meanings. In the singular sense, it is used as a science or a subject which deals with the collection, classification, tabulation, representation and interpretation of the data. In the plural sense, it is sometimes used for the numerical facts collected in the form of numbers. If we have collected information about the heights of class 6 children from ten different schools of Delhi, then this information in the form of numbers is called statistics. 1. Data : Each number, collected for giving a required information, is called the data. 2. Bar Graph (Column Graph) : Bar graph is the simplest form of presenting a data. It consists of bars (usually vertical), all of same widths. The heights of these bars are drawn according t