A dog chases a rabbit. The time it takes for the dog to hop 6 times is equal to the time it takes for the rabbit to hop 5 times. The distance the dog hops 4 times is equal to the distance the rabbit hops 7 times. The rabbit is 5.5 kilometers ahead of the dog. Ask: How far can the dog jump to catch up with the rabbit?
一只狗追赶一只兔，狗跳6次的时间与兔跳5次的时间相等，狗跳4次的距离与兔跳7次的距离相等．兔在狗前面5.5千米处，问：狗跳多远才能追上兔？
<result>5</result>