Respuesta :

500 

20 × 30 = 600

30 ÷ 2 = 15
15 × 5 = 75

600 + 75 = 675

675 - 500 = 175

Davie made 175 in profit. 
20*30=600
15*5=75
600+75=675
675-500=175 euros
Hope this helps.