Let cost of chair be x and cost of table be y. Then, x+y=750 ... (i) By selling the chair at a gain of 5% and the table at a gain of 20%, there is a profit of 16% on the whole.
Then, (x+5% of x)+(y+20% of y)=750+(16% of 750) ⇒(x+
5
100
×x)+(y+
20
100
×y)=750+
16
100
×750 ⇒100x+5x+100y+20y =75000+12000 ⇒105x+120y=87000 From Eq. (i), put y=750−x into Eq. (ii), we get ⇒105x+120(750−x)=87000 ⇒105x+90000−120x=87000 ⇒90000−87000=120x−105x ⇒3000=15x ⇒x=200 ∴y=750−200 [from Eq. (i)] =550 Hence, the original cost of the table is ₹ 550 .