Answer:To calculate Ben's profit, we need to determine the total cost of the ball pens he bought and the total revenue from selling them. Given:- Ben bought 5 ball pens at P6.00 each.- He sold each ball pen to his classmates at P8.00 each. Total Cost:Cost per ball pen = P6.00Number of ball pens bought = 5 Total Cost = Cost per ball pen (Number of ball pens) Total Cost = P6.00 (5) Total Cost = P30.00 Total Revenue:Selling price per ball pen = P8.00Number of ball pens sold = 5 Total Revenue = Selling price per ball pen (Number of ball pens) Total Revenue = P8.00 (5)Total Revenue = P40.00 Profit:Profit = Total Revenue - Total CostProfit = P40.00 - P30.00Profit = P10.00 Therefore, Ben will have a profit of P10.00 from selling 5 ball pens to his classmates.