An important question from linear equations in two variables as it was already asked in various examinations in which we have to find the value of a chair and a table if the total selling price of a chair and a table is 1520 and the profit % in a 10% on chair and 15% on table and if the profit% is 10% on chair and 25% on table then the total selling price is 1535.

Kindly solve the above problem

RS Aggarwal, Class 10, chapter 3E, question no 30

## Let the cost of chair be x and cost of table be y.

⇒ As per the question,

⇒ x+25x/100+y+10y/100=1520

⇒ 125x+110y=152000

⇒ 25x+22y=30400 —— ( 1 )

⇒ And also from the question, we get

⇒ x+10x/100+y+25y/100=1535

⇒ 110x+125y=153500

⇒ 22y+25y=30700 —— ( 2 )

⇒ Now, Multiply equation ( 1 ) with 22 and equation ( 2 ) with 25 we get,

⇒ 550x+484y=668800 —– ( 3 )

⇒ 550x+625y=767500 —— ( 4 )

⇒ Now, subtracting equation ( 2 ) by ( 1 ) we get,

⇒ y=700

⇒ Substituting value of y in equation ( 1 ) we get,

⇒ x=600

∴ Cost price of chair is Rs.600 and cost price of table is Rs.700.