Alright, so the money you make is automatically -1500 for the tools, so it's -1500. Next, the materials cost 200 dollars for each scooter, s, so we have -1500-200s. After that, we have 300 dollars for the sale of each scooter, so we have -1500-200s+300s. Adding -200 and 300 together, we have -1500+100s. To make a profit, that means 100s -1500 > 0. Dividing by 100, we have
s -15 >0 and s>15, so if you sold 16 scooters you'd make a profit. That profit would be 100*16-1500=1600-1500=100 dollars