Emily and Olive lived on a farm with their father, Gordon. One day, Emily asked her father, "Dad, what happened to the car we used to have?

Emily and Olive lived on a farm with their father, Gordon. One day, Emily asked her father, "Dad, what happened to the car we used to have?" Olive over head this and said, "Yeah, and we used to have a horse too." Gordon replied, "That tomcat and that old nag were no use. I traded them for new goat." Emily said, "Hey, that sound like a good cryptarithmetic problem. Each letter stands for a different digit, 0 through 9. No two letters stand for the same digit. TOM + NAG = GOAT Determine what each digit stands for.