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 beÂ xÂ and cost of table beÂ y.

â‡’Â As per the question,

â‡’Â Â x+25xâ€‹/100+y+10yâ€‹/100=1520

â‡’Â Â 125x+110y=152000

â‡’Â Â 25x+22y=30400Â Â Â Â Â Â Â Â —— ( 1 )

â‡’Â Â And also from the question, we get

â‡’Â Â x+10xâ€‹/100+y+25y/100â€‹=1535

â‡’Â Â 110x+125y=153500

â‡’Â Â 22y+25y=30700Â Â Â Â Â Â —— ( 2 )

â‡’Â Â Now, Multiply equation ( 1 ) with 22 and equation ( 2 ) with 25 we get,

â‡’Â Â 550x+484y=668800Â Â Â Â Â —–Â ( 3 )

â‡’Â Â 550x+625y=767500Â Â Â Â Â Â —— ( 4 )

â‡’Â Â Now, subtracting equation ( 2 ) by ( 1 ) we get,

â‡’Â Â y=700

â‡’Â Substituting value ofÂ yÂ in equation ( 1 ) we get,

â‡’Â Â x=600

âˆ´Â Cost price of chair isÂ Rs.600Â and cost price of table isÂ Rs.700.