Cheetahs run faster than lions, so when they meet, cheetahs run 40× 2 = 80km more than lions.

Cheetah is over 40 kilometers, lion is over 40 kilometers.

Therefore, the time to be satisfied =80÷(63-55)= 10 hour.

So the north-south distance = (55+63) ×10 =1180 km.

Formula: [40× 2 ÷ (63-55) ]× (63+55) =1180km.