Final answer:
To meet his goal of scoring at least 1,000 points during his high-school career, the junior basketball player needs to average 17 points per game over his last 2 years.
Step-by-step explanation:
To find out how many points the junior basketball player needs to average per game over his last 2 years, we first need to determine how many more points he needs to score to meet his goal of 1,000 points. After 2 years, he has already scored 320 points, so he needs to score an additional 1000 - 320 = 680 points in his last 2 years.
Since his team plays 20 games per year, he will have a total of 40 games over his last 2 years. To calculate the average points per game, we divide the total number of points needed (680) by the number of games (40). This gives us an average of 680 / 40 = 17 points per game.
Therefore, the junior basketball player needs to average 17 points per game over his last 2 years to meet his goal of scoring at least 1,000 points during his high-school career.