23.甲、乙二人练习跑步, 若甲让乙先跑10米, 则甲跑5秒可追上乙; 若乙比甲先跑2秒, 则甲跑4秒能追上 乙。问: 两人每秒各跑多少米? 解: 甲乙速度差为 $10 / 5=2$

Step 1 ：Form two equations based on the given information: \(x = y + 2\) and \(4x = 6y\)

Step 2 ：Substitute the first equation into the second equation and solve for y: \((y + 2) * 4 = 6y\) to get \(y = 4\)

Step 3 ：Substitute the value of y back into the first equation to find x: \(x = 4 + 2\) to get \(x = 6\)

Step 4 ：\(\boxed{\text{Final Answer: 甲每秒跑6米, 乙每秒跑4米}}\)