NCERT Class 10th Mathematics
11

NCERT Class 10th – Chapter 3 Solutions – Exercise 3.1 Pair of Two Equations in Two Variables

NCERT full solutions  here you can find full detailed solutions for all the questions  with proper format. class 10 maths ncert solutions chapter 3 exercise 3.1.

You can see the solution for complete chapter here –

EXCERCISE :-3.1

  QUE:- 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. Represent this situation algebraically and graphically. 

SOL :- 

let the present age of Aftab be x

and, present age of his daughter =y

seven year ago age of Aftab  =x-7

seven year ago age of daughter =y-7

according to the question ,

(x-7)=7(y-7)

x-7 =7y -49

x-7y =-42………………..(1)

three years hence age of Aftab = x+3

three years hence age of his daughter = y+3

according to the quetion

(x+3) =3(y+3)

x+3 =3y +9

x-3y =6………………………(2)

therefore the algebraic representation is

x-7y =-42

x =-42+7y

put value of x in equ.(2)

-42+7y-3y =6

4y = 48

y=48/4

y=12

x-7y =-42

x-7×12 =-42

x=-42 +84

x=42

present age of Aftab=42

present age of his daughter =7

THE SOLUTION is

X = -7  ,0  ,7

y= 5,   6  7

for x-3y=6 or x=6+3y

the solution is

x= 6,3,0

y=0,-1,-2

the grafical representetion is as follow

Que 2:The coach of a cricket team buys 3 bats and 6 balls for Rs 3900. Later, she buys another bat and 2 more balls              of the same kind for Rs 1300. Represent this situation algebraically and geometrically.

SOL:-

Let the cost of a bat be Rs x.
And, cost of a ball = Rs y
According to the question, the algebraic representation is

3x +6y =3900

x+2y =1300

for 3x +6y =3900

x=(3900-6y) /3

the solution table is

x 300 100 -100
y 500 600 700

for ,x +2y =1300

x= 1300-2y

the solution table is

x 300 100 -100
y 500 600 700

the graphical representetion is as follow

QUE 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.
 SOL:-
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

2x +y =160

4x +2y = 300

for 2x +y = 160

y = 160-2x

the solution table is

x 50 60 70
y 60 40 20

for 4x +2y =300

y= 300-4x/2

the solution table is

x 70 80 75
y 10 -10 0

 

the graphical representetion is as follows.

You can see the solution for complete chapter here –

Tags – class 10th maths solutions, maths solution for class 10, 10th class maths solution, mathematics solution class 10th, maths solution, 10th class maths , mathematics for class 10.

Related Posts