X Ltd$.,$ manufacturers only pens where the marginal cost of each pen is Rs$.3.$ It has fixed costs of Rs$.25,000$ per annum. Present production and sales of pens is $50,000$ units and selling price per pen is Rs$.5.$ Any sale beyond $50,000$ pens is possible only if the company reduces $20\%$ of its current selling price. However, the reduced price applies only to the additional units. The company wants a target profit of Rs$.1,00,000.$ How many pens to company must produce and sell if the target profit is to be achieved?