Answer:
8 vehicle.
Explanation:
Given: Monthly salary of salesperson is $2400
Incentive of salesperson is $250 per vehicle sold.
First, lets compute income to earned apart from salary.
∴ Deduct salary from the target amount

∴ $2000 need to be earned only through incentive, which is $250 per vehicle sold.
Now, solving to get number vehicles to be sold to earn $2000 as incentive.
Number of vehicle=

∴ 8 vehicles need to be sold by salesperson to get total earning as $4400.