Can someone who uses betting exchanges please confirm these figures for me. It is a simple dutching of 4 runners with a lay bet for one of the runners.

I would like to confirm that the figures are correct for the profit amount against each runner. I have assumed 0% exchange commission.
Also that the amount taken out of the puners' account pending result of the race is correct.

A. $7.40 bet $6 profit 24.40
B. $8.20 bet $5 profit 21.00
C. $5.20 bet $8 profit 21.60
D. $18.00 bet $3 profit (below)
D. Lay price $12 Lay $2 profit 10.00

Total Outlay = $44 (held by exchange)
Loss $20 (if no runner wins).

Thanks.