Verified Answer :

500 

20 × 30 = 600

30 ÷ 2 = 15
15 × 5 = 75

600 + 75 = 675

675 - 500 = 175

Davie made 175 in profit.

2030=600
15
5=75
600+75=675
675-500=175 euros
Hope this helps.