Question

the cost price of 400 lemon is equal to the selling price of 320 lemon .profit

Answer 1

yes this is a profit

Answer 2

let the cost price of one lemon be x. then cost price of 320 lemons = 320 x
then selling price of 320 lemons =400 x

profit = 80x rupees

profit percentage =
$\frac{profit}{c.p} \times 100$
$profit\% = \frac{80x}{320x} \times 100 = 25\%$