A shopkeeper earns the same percent of profit as well as loss by selling two similar pieces of furniture for ₹18000 and ₹10000, respectively. At what price should he sell it to earn a profit of 50%?

A shopkeeper earns the same percent of profit as well as loss by selling two similar pieces of furniture for ₹18000 and ₹10000 respectively.

Profit % = Loss %

$$\frac{\left(first\ selling\ price\ \ -\cos t\ price\right)}{\cos t\ price}\times\ 100\ =\ \frac{\left(\cos t\ price\ -\ \sec ond\ selling\ price\ \right)}{\cos t\ price}\times\ 100$$
$$\frac{\left(18000\ -\cos t\ price\right)}{\cos t\ price}\times\ 100\ =\ \frac{\left(\cos t\ price\ -\ 10000\ \right)}{\cos t\ price}\times\ 100$$

$$\left(18000\ -\cos t\ price\right)\ =\ \left(\cos t\ price\ -\ 10000\ \right)$$

$$18000\ +10000\ \ =\ \left(\cos t\ price\ +\cos t\ price\right)$$

$$28000\ \ =\ 2\times\cos t\ price$$

Cost price of furniture = ₹14000

Selling price when 50% profit earn while selling = ₹14000 of (100+50)%
= ₹14000 of 150%

= $$14000\times\ 1.5$$

= ₹21000