A CDO invests in two $$1000$ zero$-$coupon bonds. The CDO has two tranches, the Senior tranche gets paid $$1000$ before the Junior Tranche gets anything. If a bond defaults, it is estimated that the payoff will be $$0.$ It is estimated that the default probabilities are as follows.

$\backslash$table$[[,,$Bond $1,],[,,$No Default,Default,Total$],[$Bond $2,$No Default,$55\%,10\%,65\%$