Learn all Concepts of Chapter 3 Class 10 (with VIDEOS). Check - Linear Equations in 2 Variables - Class 10

Last updated at May 2, 2020 by Teachoo

Learn all Concepts of Chapter 3 Class 10 (with VIDEOS). Check - Linear Equations in 2 Variables - Class 10

Transcript

Ex 3.6, 2 Formulate the following problems as a pair of equations, and hence find their solutions: (i) Ritu can row downstream 20 km in 2 hours, and upstream 4 km in 2 hours. Find her speed of rowing in still water & speed of the current. Let the speed of boat in still water be x km/hr & let the speed of current be y km/hr Now, Speed downstream = x + y Speed upstream = x – y Ritu can row 20 km downstream in 2 hours For downstream Distance = 20 km Time = 2 hours Speed = x + y We know that Speed = (𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 )/𝑇𝑖𝑚𝑒 x + y = 20/2 x + y = 10 Ritu can row 4 km upstream in 2 hours For upstream Distance = 4 km Time = 2 hours Speed = x – y We know that Speed = (𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 )/𝑇𝑖𝑚𝑒 x – y = 4/2 x – y = 2 Hence, our equations are x + y = 10 …(1) x – y = 2 …(2) From (1) x + y = 10 x = 10 – y Putting x = 10 – y in (2) x – y = 2 (10 – y) – y = 2 – 2y = 2 – 10 – 2y = −8 y = (−8)/(−2) y = 4 Putting y = 4 in (1) x + y = 10 x + 4 = 10 x = 10 – 4 x = 6 Thus, x = 6, y = 4 is the solution Hence Speed of boat in still water = x = 6 km/hr Speed of stream = y = 4 km/hr

Chapter 3 Class 10 Pair of Linear Equations in Two Variables

Example 6
Important

Example 10 Important

Example 11 Important

Example 13 Important

Example 14 Important

Example 19 Important

Ex 3.2, 1 Important

Ex 3.2, 3 Important

Ex 3.2, 6 Important

Ex 3.5, 2 Important

Ex 3.2, 7 Important

Ex 3.6, 1 (i) and (ii) Important

Ex 3.6, 1 (iii) and (iv) Important

Ex 3.6, 1 (v) and (vi) Important

Ex 3.6, 1 (vii) and (viii) Important

Ex 3.6, 2 (i) Important You are here

Class 10

Important Questions for Exam - Class 10

- Chapter 1 Class 10 Real Numbers
- Chapter 2 Class 10 Polynomials
- Chapter 3 Class 10 Pair of Linear Equations in Two Variables
- Chapter 4 Class 10 Quadratic Equations
- Chapter 5 Class 10 Arithmetic Progressions
- Chapter 6 Class 10 Triangles
- Chapter 7 Class 10 Coordinate Geometry
- Chapter 8 Class 10 Introduction to Trignometry
- Chapter 9 Class 10 Some Applications of Trignometry
- Chapter 10 Class 10 Circles
- Chapter 11 Class 10 Constructions
- Chapter 12 Class 10 Areas related to Circles
- Chapter 13 Class 10 Surface Areas and Volumes
- Chapter 14 Class 10 Statistics
- Chapter 15 Class 10 Probability

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.