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.