Answer:
Spot ask exchange rate = $ 1.90 for 1 British Pound
Spot bid exchange rate = $ 1.89 for 1 British Pound
If you buy pounds at the spot ask exchange rate for $10,000,000. You will get $1,000,000/$1.90 = £526,315.789
If you sell these pounds (£5,263,157.89) at the bid. You will get £526,315.789*$1.89 = $994,736.84
After selling these bonds at bid, the loss will be equals to $1,000,000 - $994,736.84 = $5,263.16
Therefore, $5,263.16 would be "eaten" by the bid-ask spread