Premium Online Home Tutors

3 Tutor System

Starting just at 265/hour

Answer :

Temperature of the room in the beginning = 40°C

Temperature after 1 hour

= 40°C – 1 × 5°C = 40°C – 5°C – 35°C
Similarly, temperature of the room after 10 hours
= 40°C – 10 × 5°C = 40°C – 50°C = -10°C

- Q.1 Find each of the following products: (a) 3 × (-1) (b) (-1) × 225 (c) (-21) × (-30) (d) (-316) × (-1) (e) (-15) × 0 × (-18) (f) (-12) × (-11) × (10) (g) 9 × (-3) × (-6) (h) (-18) × (-5) × (-4) (i) (-1) ×(-2) × (-3) × 4 (j) (-3) × (-6) × (-2) × (-1)
- Q.2 Verify the following: (a) 18 × [7 + (-3)] = [18 × 7] + [18 × (-3)] (b) (-21) × [(-4) + (-6)] = [(-21) × (-4)] + [(-21) × (-6)]
- Q.3 (i) For any integer a, what is (-1) × a equal to? (ii) Determine the integer whose product with (-1) is 0. (a) -22 (b) 37 (c) 0
- Q.4 Starting from (-1) × 5, write various products showing some pattern to show (-1) × (-1) = 1
- Q.5 Find the product, using suitable properties: (a) 26 × (-48) + (-48) × (-36) (b) 8 × 53 × (-125) (c) 15 × (-25) × (-4) × (-10) (d) (-41) × 102 (e) 625 × (-35) + (-625) × 65 (f) 7 × (50 – 2) (g) (-17) × (-29) (h) (-57) × (-19) + 57
- Q.7 In a class test containing 10 questions, 5 marks are awarded for every correct answer and (-2) marks are awarded for every incorrect answer and 0 for questions not attempted. (i) Mohan gets four correct and six incorrect answers. What is his score? (ii) Reshma gets five correct answers and five incorrect answers, what is her score? (iii) Heena gets two correct and five incorrect answers out of seven questions she attempts. What is her score?
- Q.8 A cement company earns a profit of ? 8 per bag of white cement sold and a loss of Rs. 5 per bag of grey cement sold. (a) The company sells 3,000 bags of white cement and 5,000 bags of grey cement in a month. What is its profit or loss? (b) What is the number of white cement bags it must sell to have neither profit nor loss, if the number of grey bags sold is 6,400 bags.
- Q.9 Replace the blank with an integer to make it a true statement. (a) (-3) × __ = 27 (b) 5 × __ = -35 (c) __ × (-8) = -56 (d) __ × (-12) = 132

- NCERT solutions for class 7 maths chapter 1 Integers
- NCERT solutions for class 7 maths chapter 2 Fractions and Decimals
- NCERT solutions for class 7 maths chapter 3 Data Handling
- NCERT solutions for class 7 maths chapter 4 Simple Equations
- NCERT solutions for class 7 maths chapter 5 Lines and Angles
- NCERT solutions for class 7 maths chapter 6 The Triangle and its Properties
- NCERT solutions for class 7 maths chapter 7 Congruence of Triangles
- NCERT solutions for class 7 maths chapter 8 Comparing Quantities
- NCERT solutions for class 7 maths chapter 9 Rational Numbers
- NCERT solutions for class 7 maths chapter 10 Practical Geometry
- NCERT solutions for class 7 maths chapter 11 Perimeter and Area
- NCERT solutions for class 7 maths chapter 12 Algebraic Expressions
- NCERT solutions for class 7 maths chapter 13 Exponents and Powers
- NCERT solutions for class 7 maths chapter 14 Symmetry
- NCERT solutions for class 7 maths chapter 15 Visualising Solid Shapes

- NCERT solutions for class 7 science chapter 1 Nutrition in Plants
- NCERT solutions for class 7 science chapter 2 Nutrition In Animals
- NCERT solutions for class 7 science chapter 3 Fibre to Fabric
- NCERT solutions for class 7 science chapter 4 Heat
- NCERT solutions for class 7 science chapter 5 Acids Bases and Salts
- NCERT solutions for class 7 science chapter 6 Physical and Chemical Changes
- NCERT solutions for class 7 science chapter 7 Weather, Climate and Adaptations of Animals to Climate
- NCERT solutions for class 7 science chapter 8 Winds, Storms and Cyclones
- NCERT solutions for class 7 science chapter 9 soil
- NCERT solutions for class 7 science chapter 10 Respiration in Organisms
- NCERT solutions for class 7 science chapter 11 Transportation in Animals and Plants
- NCERT solutions for class 7 science chapter 12 Reproduction In Plant
- NCERT solutions for class 7 science chapter 13 Motion and Time
- NCERT solutions for class 7 science chapter 14 Electric Current and Its Effects
- NCERT solutions for class 7 science chapter 15 Light
- NCERT solutions for class 7 science chapter 16 Water: A Precious Resource
- NCERT solutions for class 7 science chapter 17 Forests: Our Lifeline
- NCERT solutions for class 7 science chapter 18 Waste Water Story