Quick answer = [$45.00] If he spent $25.00 and he is left with $20.00 then...
$25.00 +$20.00 = $45.00
{Example} Lets say you had $45 and you went to buy some fast food.. okay in the end your whole meal cost $25 so if your taking that $25 out of your $45 then you would be left with $20. So yeah......