Human: There are 516 cars in a parking lot. One-third are blue, one-half are red, and the rest are black. How many black cars are on the lot? Assistant: 
How many blue cars are in the parking lot? ** Blue = 516 * (1/3) = <<516*(1/3)=172>>172 cars
How many red cars are in the parking lot? ** Red = 516 * (1/2) = <<516*(1/2)=258>>258
How many black cars are in the parking lot? ** Black = 516 - (172 + 258) = 86
How many black cars are on the lot? ** There are 86 black cars on the lot.
#### 86