Exercise 3.1 class 8

NCERT Solutions for Class 7 Maths Chapter 3 Data Handling Ex 3.1 • • • • NCERT Solutions for Class 7 Maths Chapter 3 Data Handling Exercise 3.1 Ex 3.1 Class 7 Maths Question 1. Find the range of heights of any ten students of your class. Solution: Let us have the heights of 10 students are as follows: 140 cm, 141.5 cm, 138 cm, 150 cm, 161 cm, 138 cm, 140.5 cm, 135.5 cm, 160 cm, 158 cm Here, minimum height = 135.5 cm Maximum height =161 cm ∴ Range = Maximum height – Minimum height = 161 cm — 135.5 cm = 25.5 cm Hence, the required range = 25.5 cm. Ex 3.1 Class 7 Maths Question 2. Organise the following marks in a class assessment in a tabular form. 4, 6, 7, 5, 3, 5, 4, 5, 2, 6, 2, 5, 1, 9, 6, 5, 8, 4, 6, 7 (i) Which number is the highest? (ii) Which number is the lowest? (iii) What is the range of the data? (iv) Find the arithmetic mean. Solution: Let us form a frequency distribution table: (i) 9 is the highest marks. (ii) 1 is the lowest marks. (iii) Range = Max. marks – Min. marks = 9 – 1 = 8 (iv) Arithmetic mean = \(\frac=10.67\) Mean score of C = 10.67 While mean score of A = 12.5 Clearly, A is the best performer. Ex 3.1 Class 7 Maths Question 6. The marks (out of 100) obtained by a group of students in a science test are 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75. Find the (i) highest and the lowest marks obtained by the students. (ii) range of the marks obtained. (iii) mean marks obtained by the group. Solution: Marks obtained are: 85, 76, 90, 85, 39, 48, 56, 95, 81 and...

Previous Next Access Answers of Maths NCERT Class 8 Chapter 3 – Understanding Quadrilaterals Exercise 3.1 Page: 41 1. Given here are some figures.  Classify each of them on the basis of the following. Simple curve (b) Simple closed curve (c) Polygon (d) Convex polygon (e) Concave polygon Solution: a) Simple curve: 1, 2, 5, 6 and 7 b) Simple closed curve: 1, 2, 5, 6 and 7 c) Polygon: 1 and 2 d) Convex polygon: 2 e) Concave polygon: 1 2. How many diagonals does each of the following have? a) A convex quadrilateral (b) A regular hexagon (c) A triangle Solution: a) A convex quadrilateral: 2. b) A regular hexagon: 9. c) A triangle: 0 3. What is the sum of the measures of the angles of a convex quadrilateral? Will this property hold if the quadrilateral is not convex? (Make a non-convex quadrilateral and try!) Solution: Let ABCD be a convex quadrilateral. From the figure, we infer that the quadrilateral ABCD is formed by two triangles, i.e. ΔADC and ΔABC. Since we know that sum of the interior angles of a triangle is 180°, the sum of the measures of the angles is 180° + 180° = 360° Let us take another quadrilateral ABCD which is not convex . Join BC, such that it divides ABCD into two triangles ΔABC and ΔBCD. In ΔABC, ∠1 + ∠2 + ∠3 = 180° (angle sum property of triangle) In ΔBCD, ∠4 + ∠5 + ∠6 = 180° (angle sum property of triangle) ∴, ∠1 + ∠2 + ∠3 + ∠4 + ∠5 + ∠6 = 180° + 180° ⇒ ∠1 + ∠2 + ∠3 + ∠4 + ∠5 + ∠6 = 360° ⇒ ∠A +...

Table of Contents • • • • • • • • • • • • • • • • • NCERT Solutions for Class 8 Maths Exercise 3.1 Class 8 Maths book solutions are available in PDF format for free download. These ncert book chapter wise questions and answers are very helpful for CBSE exam. CBSE recommends NCERT books and most of the questions in CBSE exam are asked from NCERT text books. Class 8 Maths chapter wise NCERT solution for Maths Book all the chapters can be downloaded from our website and myCBSEguide mobile app for free. NCERT solutions for Class 8 Maths Understanding Quadrilaterals NCERT Solutions for Class 8 Maths Understanding Quadrilaterals Class –VIII Mathematics (Ex. 3.1) NCERT SOLUTION 1. Given here are some figures: Classify each of them on the basis of the following: (a) Simple curve (b) Simple closed curve (c) Polygon (d) Convex polygon (e) Concave polygon Ans. (a) Simple curve (b) Simple closed curve (c) Polygons (d) Convex polygons (e) Concave polygon 2. How many diagonals does each of the following have? (a) A convex quadrilateral (b) A regular hexagon (c) A triangle Ans. (a) A convex quadrilateral has two diagonals. Here, AC and BD are two diagonals. (b) A regular hexagon has 9 diagonals. Here, diagonals are AD, AE, BD, BE, FC, FB, AC, EC and FD. (c) A triangle has no diagonal. NCERT Solutions for Class 8 Maths Exercise 3.1 3. What is the sum of the measures of the angles of a convex quadrilateral? Will this property hold if the quadrilateral is not convex? (Make a non-convex quad...