# NCERT solution class 10 chapter 3 Pair of Linear Equations in Two Variables exercise 3.1 mathematics

## EXERCISE 3.1

#### Question 1:

Aftab tells his daughter, “Seven years ago, I was seven times as old as you were then. Also, three years from now, I shall be three times as old as you will be.” (Isn’t this interesting?) Represent this situation algebraically and graphically.

Let the present age of Aftab be x.

And, present age of his daughter = y

Seven years ago,

Age of Aftab = x − 7

Age of his daughter = y − 7

According to the question, Three years hence,

Age of Aftab = x + 3

Age of his daughter = y + 3

According to the question, Therefore, the algebraic representation is For , The solution table is

 x − 7 0 7 y 5 6 7

For , The solution table is

 x 6 3 0 y 0 − 1 − 2

The graphical representation is as follows. #### Question 3:

The cost of 2 kg of apples and 1 kg of grapes on a day was found to be Rs 160. After a month, the cost of 4 kg of apples and 2 kg of grapes is Rs 300. Represent the situation algebraically and geometrically.

Let the cost of 1 kg of apples be Rs x.

And, cost of 1 kg of grapes = Rs y

According to the question, the algebraic representation is For , The solution table is

 x 50 60 70 y 60 40 20

For 4x + 2y = 300, The solution table is

 x 70 80 75 y 10 −10 0

The graphical representation is as follows. error: Content is protected !! 