Answer:
The amount of commission payable to Alder is $0
Step-by-step explanation:
Even though Toni promised to pay Alder 5% commission sale of the farm house,Alder could not get the promised commission since the buyer ,Deena did not buy the farm house through Alder instead bought the farm house directly from the owner,Toni.
Toni later found a buyer that was willing to pay a higher amount,however the sale could not take place because the farm house has been sold to the first mover.