Find Cost Price per pen

Calculate the cost price of a single pen by dividing the total cost by the number of pens: $\text{CP} = \frac{50}{10} = \text{Rs. } 5$.

$\text{CP of 1 pen} = \frac{50}{10} = 5$

Find Selling Price per pen

Calculate the selling price of a single pen by dividing the total selling price by the number of pens sold: $\text{SP} = \frac{60}{8} = \text{Rs. } 7.5$.

$\text{SP of 1 pen} = \frac{60}{8} = 7.5$

Calculate Profit Percentage

Apply the profit percentage formula using the per-unit values: $\text{Profit } \% = \frac{7.5 - 5}{5} imes 100 = 50\%$.

$ext{\text{Profit} } \% = \frac{7.5 - 5}{5} imes 100 = 50\%$