You need to make the conversion between American dollars and Canadian dollars, such that:

`$900 USD = $ 900*$1.115 CAD = $ 1003.5 CAD`

You need to consider the commision charged by the bank, such that:

`2.35%*$ 1003.5 CAD = 2.35/100*$ 1003.5 CAD = $ 23.58 CAD`

Convert this amount in American dollars, such that:

`x = ($ 23.58 CAD)/($1.115 CAD) => x = $ 21.15 USD`

You need to add the amount charged by the bank to the amount of $900 USD, such that:

`$ 21.15 USD+ $ 900 USD = $ 921.15 USD`

Convert the American dollars into Canadian dollars, such that:

`$ 921.15 USD = $ 921.15 USD*$1.115 CAD = $1027.08 CAD`

Hence, if you want $ 900 USD for a trip, you need to pay to the bank the following Canadian amount of `$1027.08 CAD.`