It's six
2 4 6 8 10
3 6 9 12 15
The exchange rate is 60:50 (us:euro)
if you have 70 euros, then x:70
60(x) : 70(50)
60x /60 : 3500/60
x = 58.33
seventy euro dollars = $ 58.33 on that particular day
hope this helps
1.31 + 1.23 = 2.54
2.54 + 1.23 = 3.77
So, keeping that up,
3.77 + 1.23 = 5