Let the cost of each good mango be denoted by 'g'.
The cost of each medium-quality mango is represented as 'm' \(=\frac{g}{2}\)
Total Cost Price \(=80+40\frac{g}{2}=100g\)
The overall selling price is given by \(120(0.9g)\), which equals \(108g. \)
The total profit is \(8\%.\)