Ming Jie is playing an online game. He earns 5 points when his arrow hits the red targets and loses 2 points when his arrow hits the blue targets After some arrows, he earned 65 points.
(a) What is the least number of arrows he used to achieve 65 points?
(b) To win the game, he cannot use more than 30 arrows to earn at least 80 points What is the most number of blue targets he can hit?