Question

A shopkeeper buys 100 pens for rs.200, and sells 20 of them at a gain of 10%. At what gain percent must he sell the remainder so as to gain 20% in all?

Please tell me full solution..
I know the answer but I don't know how I can solve this..
ANSWER is 22.5%​

Answer 1

Answer:

Step-by-step explanation:

The gain percentage is 20%.

Step-by-step explanation:

For Rs. 250, the shopkeeper purchased 100 eggs and among them, 10 eggs were broken.

Then the cost of purchase (CP) = 250 Rs.

So, the remaining number of eggs is (100 - 10) = 90.

If he sold the renaming eggs at the rate of rupees 40 per dozen, then the sale price (SP) of the eggs will be \frac{40 \times 90}{12} = 300

12

40×90

=300 Rs.

Since the cost of the purchase is less than the sale price, so, he makes a gain.

So, the gain percentage is \frac{300 - 250}{250} \times 100\% = 20\%

250

300−250

×100%=20% . (Answer)