Question

3 chairs and 2 tables cost rs 700 and 5 chairs and 3 tables cost rs 1100. A purchased 2 chairs and 2 tables and paid rs 700 to the shopkeeper.

Shopkeeper said 'It is not correct amount' and returned him the balance.

Which value is depicted by the shopkeeper?

Answer 1

LET THE COST OF 1 CHAIR AND 1 TABLE BE X AND Y.

3X+2Y = 700

3X= 700-2Y

X = 700-2Y/3......(1)

again,

5X+3Y = 1100

PUT THE VALUE OF X IN,

5X+3Y = 1100

700-2Y/3 +3Y = 1100

700-2Y+9Y / 3 = 1100

700-2Y+9Y = 1100×3 = 3300

7Y = 3300-700

Y = 371.42.

Answer 2

Let cost chair be Rs x and table be Rs y.
[3x+2y=700]X3                        →1
[5x+3y=1100]X2                       →2
By elimination method in →1 and →2.
9x  +6y=2100
10x+6y=2200
(-)  (-)    (-)        
-x        = -100
         x=Rs 100                         →3
By substituting Eqn. →3 in →1.
3x+2y=700
3(100)+2y=700
300+2y=700
2y=700-300
2y=400
y=400/2
y=Rs 200
To find 2x+2y.
2x+2y=2(100)+2(200)
          =200+400
          =Rs 600
The Shopkeeper returned him Rs 100.
The Shopkeeper is honest.