Question

The profit obtained on the sale of 100 pens was equal to the selling price of 40 pens. The profit obtained on the sale of 120 such pens will be equal to the cost price of how many such pens?
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Answer 1

HOPE IT HELPS!!!!!!!!!

Answer 2

Answer:

Step 1: Finding Cost price of one pen -

Let the selling price of one pen be Rs. a

∴ Selling price of 100 pens = Rs. a×100 = Rs. 100a

According to question,

Profit = selling price of 20 pens

Profit = Rs. a × 20 = Rs. 20a

As we know, Profit = Selling price - Cost price

                    ∴ Cost price = Selling price - Profit

                                         = 100a - 20a = Rs. 80a

The cost price of 100 pens, C.P. = Rs. 80a

The cost price of one pen = Rs. 80a/100 = Rs. 0.8a

Step 2: Finding Profit % -

Now, we will find the profit percentage,

Profit % = $\frac{Profit}{C.P.}$ × 100

            = (20a/80a)×100% = 25 %

Step 3: Finding profit on 120 pens -

Profit percentage is same for any number of pens.

So for 120 such pens,

Cost price, C.P. = 0.8a×120 = Rs. 96a

Profit % = $\frac{Profit}{C.P.}$ × 100

Profit = (Profit %/100) × C.P.

Profit = (25/100) × 96a

         = Rs. 24a

         = Rs. 0.8a × 30

But 0.8 a = Cost price of one pen

∴ Profit = 30×Cost price of one pen

Hence, The profit obtained on the sale of 120 such pens will be equal to the cost price of 30 such pens.

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