75. $A, B$ are two places 7200 meters apart. Jia and Yi start from $A$ and $B$ respectively at the same time, walking towards each other, and they meet at a point 2400 meters from $B$. If Yi's speed is increased to three times his original speed, then they can meet 10 minutes earlier. Jia walks $\qquad$ meters per minute.
Answer: 192