- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.1
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.2
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.3
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.4
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.5
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.6
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.7
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.8
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.9
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.11
- RD Chapter 3- Pair of Linear Equations in Two Variables Ex-VSAQS

RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.1 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.2 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.3 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.4 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.5 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.6 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.7 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.8 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.9 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-3.11 |
RD Chapter 3- Pair of Linear Equations in Two Variables Ex-VSAQS |

**Answer
1** :

Distance between two points A and B = 70 km

Let speed of first car starting from A = x km/hr

and speed of second car starting from B =y km/hr

When these start in the some direction, they meet after 7 hours

Distance travelled by the first car = 7x km

and by second car = 7y km

When these travel in opposite direction, they meet after 1 hour then distance travelled by first car = x km

and by second car = y km

x + y = 70 ….(ii)

Adding (i) and (ii)

2x = 80

=> x = 40

and subtracting (i) from (ii)

2y = 60

=> y = 30

Speed of first car = 40 km/hr

and speed of second car = 30 km/hr

**Answer
2** :

Let the speed of sailor in still water = x km/ hr

and speed of water = y km/hr

Distance covered = 8 km

**Answer
3** :

Let the speed of stream = y km/hr

and speed of boat = x km/hr

Speed of boat downstream = (x + y) km/hr

In first case, and up stream = (x – y) km/hr

Upstream distance = 30 km

and down distance = 44 km

Total time taken = 10 hrs

In second case,

upstream distance = 40 km

and downstream distance = 55 km

Total time taken = 13 hrs

**Answer
4** :

Let the speed of boat = x km/hr

and speed of stream = y km/hr

In first case,

Distance covered upstream = 24 km

and down stream = 28 km

Total time taken = 6 hours

In second case,

Distance covered upstream = 30 km

and downstream = 21 km

Total time taken = 6 = 13/2 hrs.

**Answer
5** :

Let the distance = x km

and let certain speed = y km/hr

**Answer
6** :

Let the speed of the stream be v km/h

Given that, a person rowing in still water = 5 km/h

The speed of a person rowing in downstream = (5 + v) km/h

and the speed of a person Has rowing in upstream = (5 – v) km/h

Now, the person taken time to cover 40 km downstream,

**Answer
7** :

Total distance = 769 km

Let the speed of train = x km/hr

and speed of car = y km/hr

Time taken = 8 hours

In first case, distance travelled by train = 160 km

and rest distance 760 – 160 = 600 km by car

Time taken

**Answer
8** :

Total journey = 600 km

Let the speed of train. = x km/hr

and speed of car = y km/hr

In first case,

Journey by train = 400 km

Journey by car = 600 – 400 = 200 km