If there is a $5,000 deposit, that means the amount to be mortgaged is $82,500. Calculating 3% of that amount:
0.03 * $82500 = $2475
The closing costs of the loan are $2,475. When they close the deal, they must bring that PLUS the down payment to the table, or $7,475.
If they are putting 30% down:
0.30 * $310000 = $93000
Add that to all of the other costs listed, they'll need to bring $94,165.
Discarding the $25,000, the Paltrows are asking for a $100,000 mortgage loan. 2% of that is $2,000, and so the total mortgage is for $102,000.
I can't answer this because I don't know how the interest is charged