Question

A merchant bought some watches at Rs.6000 per dozen and an equal number at Rs.15000 per 25 pieces. He sold them at Rs.17000 per 25 pieces thus making a total profit of Rs.39000.

How many watches did he buy?

Answer 1

Given :

A merchant bought some watches at Rs. 6000 per dozen and an equal number at Rs. 15,000 per 25 pieces.

He sold them at Rs. 17,000 per 25 pieces and made profit of Rs. 39,000.

To Find :

The number of watches he purchased.

Solution :

The merchant bought some watches for the amount = Rs. 6000/dozen

Cost Price of each watch  = $\frac{6000}{12}$ = 500 Rs.

Merchant bought some watches for the amount = Rs. 15000/25 pieces

Cost Price of each watch  = $\frac{15000}{25}$ = 600 Rs.

Selling price of each watch = $\frac{17000}{25}$ = 680 Rs.

Let the merchant bought the number of watches = n + n = 2n

Profit = selling price - cost price

680 × 2n -(n × 500 + n × 600) = 39,000

1360n - (500n + 600n) = 39,000

1360n - 1100n = 39,000

260n = 39,000

n = $\frac{39000}{260}$

n = 150

He bought total (150 + 150) = 300 watches.